Author: claimsbot

1. A metalization of a field effect power transistor having lateral semiconductor layers on an insulator substrate or an intrinsically conducting or doped semiconductor substrate, wherein the lateral semiconductor layers have different band gaps such that a two-dimensional electron gas can form in a semiconductor depletion layer of each lateral semiconductor layer, wherein the two-dimensional electron gas can flow between source electrode contact areas and drain electrode contact areas upon application of a voltage between source and drain through the lateral semiconductor depletion layers, wherein current intensity in a channel region between the source electrode contact areas and the drain electrode contact areas is controllable via gate electrode contact areas by means of a gate voltage, wherein a metalization of the source electrode contact areas, a metalization of the drain electrode contact areas and a metalization of the gate electrode contact areas are on a semiconductor surface of the semiconductor layers and have a plurality of metalization layers, between which insulation layers are arranged in a lateral direction, wherein the metalization layers both for the source electrode metalization and for the drain electrode metalization have a comb structure with contact fingers, wherein the contact fingers of the source electrode metalization and of the drain electrode metalization intermesh in a spaced-apart fashion and each contact finger has a contact finger foot and a contact finger tip, wherein a width of the contact finger foot is greater than a width of the contact finger tip.
2. The metalization of claim 1, wherein the width at the contact finger tip approaches zero.
3. The metalization of claim 1, wherein the contact fingers of the source electrode metalization and of the drain electrode metalization form equilateral triangle having an acute angle \u03b3 of between 0\xb0\u2266\u03b3\u22663 relative to a base of the equilateral triangle.
4. The metallization of claim 3, wherein the base has a base width c of between 30 \u03bcm\u2266c\u226640 \u03bcm, preferably c=36 \u03bcm.
5. The metalization of claim 1, wherein a contact finger tip of a triangular contact finger of the drain electrode metalization is arranged in the region of the contact finger feet of two triangular contact fingers of the source electrode metalization.
6. The metalization of claim 1, wherein the plurality of metalization layers comprises a first selective contact layer on the semiconductor surface in corresponding first contact window openings for the source, drain and gate of a first insulation layer and a selective ohmic contact layer arranged on the selective first contact layer.
7. The metalization of claim 6, wherein the plurality of metalization layers of the source electrode metalization and of the drain electrode metalization have on the respective selective ohmic contact layers in corresponding second contact window openings of a second insulation layer a field plate metalization layer which extends areally on the second insulation layer and covers a multiple of the area of the second contact window openings of the second insulation layer.
8. The metalization of claim 6, wherein the field plate metalization layer of the source electrode metalization and the field plate metalization layer of the drain electrode metalization are spaced apart from one another and are arranged in a manner areally interlocked with respect to one another in accordance with a structure of the source electrode contact areas and the drain electrode contact areas.
9. The metalization of claim 8, wherein the plurality of metalization layers of the source electrode metalization and of the drain electrode metalization have on the respective field plate metalization layer in corresponding third contact window openings of a third insulation layer a power metalization layer of the source electrode contact areas and the drain electrode contact areas which extends areally on the third insulation layer and covers a multiple of the area of the third contact window openings of the third insulation layer.
10. The metalization of claim 9, wherein the first, the second and the third contact window openings of the source electrode metalization and of the drain electrode metalization have comb and contact finger structures of identical size.
11. The metalization of claim 9, wherein the power metalization of the drain electrode contact areas beyond edges of triangular contact fingers of the mutually interlocked field plate metalization layer, and wherein the field plate metalization layer of the source electrode contact areas projects beyond edges of a power metalization and with the field plate metalization layer the gate electrode contact areas arranged on both sides of the source electrode contact areas are covered and are electrically insulated therefrom by the second insulation layer.
12. The metalization of claim 7, wherein the field plate metalization layer of the mutually interlocked source electrode contact areas and of the drain electrode contact areas comprises a copper alloy and the power metalizations of the source electrode contact areas and of the drain electrode contact areas comprise an aluminum alloy.
13. The metalization of claim 9, wherein the power metalization of the drain electrode contact areas does not overlap the ohmic contact layer of the gate electrode contact areas and has a minimum distance d with respect to the gate electrode contact areas in accordance with its voltage class with 150 V\u03bcm.
14. The metalization of claim 9, wherein the power metalization of the drain electrode contact areas is arranged centrally between two interlocked power metalizations of the source electrode contact areas, the interlocked power metalizations being arranged in a mirror-inverted fashion with respect to one another, such that the interlocking of the power metalization of the drain electrode contact area has a fir tree structure.
15. The metalization of claim 1, wherein the lateral semiconductor layers comprise one of the following semiconductor material systems: SiSiGe; AlGaAsGaAs; InGaAsInPAlInAs; AlInNGaN; and AlGaNGaN.
16. The metalization of claim 9, wherein the power metalization of the mutually interlocked power metalization of the source electrode contact areas and of the power metalization of the drain electrode contact area have a distance a from one another in accordance with their voltage class of 150 V\u03bcm and wherein 1 \u03bcm\u2266a\u226610 \u03bcm.
17. The metalization of claim 9, wherein trapezoidal fingers of the power metalization have at the finger foot a base angle \u03b1S for the source contact fingers and respectively \u03b1D for the drain contact fingers, where \u03b1S and \u03b1D are not equal and wherein the base angle \u03b1S of the source contact fingers is not equal to the base angle \u03b2S of trapezoidal fingers of the source field plate metalization layer and the base angle \u03b1D of the drain contact fingers is not equal to the base angle \u03b2D of trapezoidal fingers of the drain field plate metalization layer.
18. The metalization of claim 1, wherein the field effect power transistor is an HEM transistor (high electron mobility transistor), an MODFE transistor (modulation-doped field-effect transistor), a TEGFE transistor (two dimensional electron-gas field-effect transistor), an SDH transistor (selectively doped heterojunction transistor) or an HFE transistor (heterojunction field-effect transistor).
19. The metalization of claim 1, wherein the field effect power transistor is an HEM transistor having a highly doped n-conducting aluminum gallium nitride layer as a topmost junction semiconductor layer with respect to the source electrode contact areas, the drain electrode contact areas and the gate electrode contact areas, wherein the aluminum gallium nitride layer is arranged on an intrinsically conducting, undoped, carbon- or FE-doped gallium nitride layer.
20. The metalization of claim 1, wherein the semiconductor layers are arranged on an undoped silicon carbide substrate or a sapphire substrate.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A clamp assembly for flexible tubing, comprising:
first and second clamp portions, each having first and second ends, associated with and self-securable to each other to define a tubing-receiving channel therebetween for a length of flexible tubing to be received thereinto, the first and second clamp portions axially moveable relative to one another in a direction transverse to the tubing-receiving channel between a first position in which the length of flexible tubing is substantially unengaged while extending through the assembly of the first and second clamp portions, and a second position, whereby the first and second clamp portions compress and occlude the flexible tubing therebetween when in the second position,
wherein one of the first and second clamp portions include at least one tubing-engaging rib for engaging and pressing the flexible tubing against an impingement surface of the other of the first and second clamp portions when the first and second clamp portions are in the second position sufficiently to occlude the flexible tubing and
wherein the second clamp portion includes a pair of detents that cooperate with a corresponding pair of recesses of the first clamp portion to secure together the clamp assembly when in the first position, each detent is defined on a free end of a spring arm defined on a respective latch arm of the second clamp portion spaced from the free end thereof wherein the spring arm is deflectable inwardly during assembly of the first and second clamp portions by one of the opposing side walls of the first clamp portion.
2. The clamp assembly of claim 1, wherein the shape of the first and second clamp portions when in the second position, is generally oblong.
3. The clamp assembly of claim 1, wherein the first clamp portion is a housing having a first end and a second end, a pair of opposing side walls joining the first and second ends, and the tubing-receiving channel extends through openings in respective ones of the opposing side walls of the housing.
4. The clamp assembly of claim 3, wherein the openings in the opposing side walls of the first clamp portion are oblong such that the tubing is translatable therewithin transversely with respect thereto when the second clamp portion is moved between the first and second positions with respect to the first clamp portion.
5. A clamp assembly for flexible tubing, comprising:
first and second clamp portions, each having first and second ends, associated with and self-securable to each other to define a tubing-receiving channel therebetween for a length of flexible tubing to be received thereinto, the first and second clamp portions being affixable to each other to define a first position in which the length of flexible tubing is substantially unengaged while extending through the assembly of the first and second clamp portions, and a second position, whereby the first and second clamp portions compress and occlude the flexible tubing therebetween when in the second position,
wherein one of the first and second clamp portions include at least one tubing-engaging rib for engaging and pressing the flexible tubing against an impingement surface of the other of the first and second clamp portions when the first and second clamp portions are in the second position sufficiently to occlude the flexible tubing, and wherein the second clamp portion has a pair of detents and the first clamp portion has a pair of recesses associated with respective ones of the detents and the recesses are shallow grooves defined into inside surfaces of the opposing side walls of the first clamp portion extending in a direction between the first and second ends thereof.
6. A clamp assembly for flexible tubing, comprising:
first and second clamp portions, each having first and second ends, associated with and self-securable to each other to define a tubing-receiving channel therebetween for a length of flexible tubing to be received thereinto, the first and second clamp portions being affixable to each other to define a first position in which the length of flexible tubing is substantially unengaged while extending through the assembly of the first and second clamp portions, and a second position, whereby the first and second clamp portions compress and occlude the flexible tubing therebetween when in the second position,
wherein one of the first and second clamp portions include at least one tubing-engaging rib for engaging and pressing the flexible tubing against an impingement surface of the other of the first and second clamp portions when the first and second clamp portions are in the second position sufficiently to occlude the flexible tubing, and wherein the impingement surface of the other of the first and second clamp portions is defined by at least one tubing-engaging rib to assist in occluding the flexible tubing when the clamp assembly is in the second position.
7. The clamp assembly of claim 6, wherein the impingement surface is defined by two tubing-engaging ribs of the one of the first and second clamp portions that extend to either side of the at least one tubing-engaging rib of the other thereof such that all of the tubing-engaging ribs cause the flexible tubing to be deformed into a tortuous path when the clamp assembly is in the second position, occluding the tubing.
8. The clamp assembly of claim 6, wherein each tubing-engaging rib concludes in a rounded tubing-engaging surface.
9. A clamp assembly for flexible tubing, comprising:
first and second clamp portions, each having first and second ends, associated with and self-securable to each other to define a tubing-receiving channel therebetween for a length of flexible tubing to be received thereinto, the first and second clamp portions being affixable to each other to define a first position in which the length of flexible tubing is substantially unengaged while extending through the assembly of the first and second clamp portions, and a second position, whereby the first and second clamp portions compress and occlude the flexible tubing therebetween when in the second position,
wherein one of the first and second clamp portions include at least one tubing-engaging rib for engaging and pressing the flexible tubing against an impingement surface of the other of the first and second clamp portions when the first and second clamp portions are in the second position sufficiently to occlude the flexible tubing, and wherein the one of the first and second clamp portions includes a pair of outer tubing-engaging ribs offset along the tubing-receiving channel from the at least one tubing-engaging rib to extend along outer sides of respective ones of the pair of tubing-engaging ribs of the other of the first and second clamp portions.
10. The clamp assembly of claim 9, wherein the outer tubing-engaging ribs extend in respective diverging directions with respect to the direction in which the at least one tubing-engaging rib extends.
11. A clamp assembly for flexible tubing, comprising:
first and second clamp portions, each having first and second ends, associated with and self-securable to each other to define a tubing-receiving channel therebetween for a length of flexible tubing to be received thereinto, the first and second clamp portions being affixable to each other to define a first position in which the length of flexible tubing is substantially unengaged while extending through the assembly of the first and second clamp portions, and a second position, whereby the first and second clamp portions compress and occlude the flexible tubing therebetween when in the second position,
wherein one of the first and second clamp portions include at least one tubing-engaging rib for engaging and pressing the flexible tubing against an impingement surface of the other of the first and second clamp portions when the first and second clamp portions are in the second position sufficiently to occlude the flexible tubing, and wherein the impingement surface of one of the first and second clamp portions is defined by two tubing-engaging ribs, and the impingement surface of the other thereof is defined by three tubing-engaging ribs offset along the tubing channel from the two tubing-engaging ribs, such that all of the tubing-engaging ribs cause the flexible tubing to be deformed into a tortuous path when the clamp assembly is in the second position, occluding the tubing.
12. A clamp assembly for flexible tubing, comprising:
first and second clamp portions, each having first and second ends, associated with and self-securable to each other to define a tubing-receiving channel therebetween for a length of flexible tubing to be received thereinto, the first and second clamp portions axially moveable relative to one another in a direction transverse to the tubing-receiving channel between a first position in which the length of flexible tubing is substantially unengaged while extending through the assembly of the first and second clamp portions, and a second position, whereby the first and second clamp portions compress and occlude the flexible tubing therebetween when in the second position,
wherein one of the first and second clamp portions include at least one tubing-engaging rib for engaging and pressing the flexible tubing against an impingement surface of the other of the first and second clamp portions when the first and second clamp portions are in the second position sufficiently to occlude the flexible tubing and
wherein the second clamp portion includes at least one latch arm projecting longitudinally from the second end thereof and having a free end that latchingly engages a catch of the first clamp portion when in the second position, wherein each at least one latch arm is deflectable in a direction generally perpendicular to the direction of movement of the first and second clamp portions.
13. The clamp assembly of claim 12, wherein the at least one latch arm extends within one of opposing side walls of the first clamp portion and the catch is provided at the second end thereof.
14. The clamp assembly of claim 13, wherein the second clamp portion has two latch arms extending from respective opposing sides thereof and that extend on opposed sides of the tubing-receiving channel through the first clamp portion, which has respective catches associated with the two latch arms.
15. The clamp assembly of claim 14, wherein the latch arm free ends project through latch arm channels of the first clamp portion and beyond the second end thereof to engage the respective catches, and are exposed to be manually engaged to unlatch the latch arms.
16. The clamp assembly of claim 15, wherein the first clamp portion includes a boss between the latch arm channels projecting a distance from the second end at least equal to the distance that the free ends of the latch arms of the second clamp portion extend when in the second position.
17. The clamp assembly of claim 15, wherein the first clamp portion includes a pair of recesses into top and bottom surfaces spaced from the second end thereof into which free ends of the latch arms of the second clamp portion snap when the clamp assembly is in its first position.

What is claimed is:

1. A method for detecting a nuclease-mediated cleavage of a target nucleic acid, which method comprises:
(a) hybridizing a target nucleic acid to a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor;
(b) contacting the probe-target hybrid with an agent having nuclease activity in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe; and
(c) detecting the release of the probe by measuring a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid.
2. The method of claim 1, wherein the agent is an enzyme having an RNase H activity.
3. The method of claim 2, wherein the agent is selected from the group consisting of HIV reverse transcriptase, E. coli RNase H1, E. coli RNase H2, Human RNase H1, Human RNase H2, hammerhead ribozyme, HBV reverse transcriptase, and integrase.
4. The method of claim 1, wherein the probe is DNA, and the target is the DNA:RNA hybrid substrate.
5. The method of claim 1, wherein the probe is at least 18 nucleotides in length.
6. The method of claim 1, wherein the probe, when unhybridized to the target nucleic acid, adopts a hairpin secondary structure conformation that brings the fluorophor and quencher into proximity.
7. The method of claim 1, wherein the nuclease reaction is performed in the presence of a compound, wherein a difference in the rate of the decrease in the flourescent signal of the flourophor during the nuclease reaction, as compared to the decrease observed when the same reaction is conducted in the absence of the compound, is indicative of the ability of the compound to either inhibit or enhance the nuclease activity of the agent.
8. The method of claim 1, which further comprises monitoring the flourescent signal of the flourophor during the nuclease reaction.
9. A method for measuring a RNase H activity of an agent, which method comprises:
(a) hybridizing a target RNA to a fluorescently labeled oligodesoxyribonucleotide probe complementary to the target RNA and containing a flourophor at one terminus and a quenching at the other terminus, wherein (i) when the probe is unhybridized to the target RNA, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor;
(b) contacting the probe-target hybrid with the agent in an amount sufficient to selectively cleave the target RNA and thereby release the intact probe; and
(c) measuring a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid.
10. The method of claim 9, wherein the agent is an enzyme having an RNase H activity.
11. The method of claim 10, wherein the agent is selected from the group consisting of HIV reverse transcriptase, E. coli RNase H1, E. coli RNase H2, Human RNase H1, Human RNase H2, hammerhead ribozyme, HBV reverse transcriptase, and integrase.
12. The method of claim 9, wherein the probe is at least 18 nucleotides in length.
13. The method of claim 9, wherein the probe, when unhybridized to the target RNA, adopts a hairpin secondary structure conformation that brings the fluorophor and quencher into proximity.
14. The method of claim 9, wherein the RNase H-mediated reaction is performed in the presence of a compound, wherein a difference in the rate of the decrease in the flourescent signal of the flourophor during the RNase H-mediated reaction, as compared to the decrease observed when the same reaction is conducted in the absence of the compound, is indicative of the ability of the compound to either inhibit or enhance the RNase H activity of the agent.
15. The method of claim 9, which further comprises monitoring the flourescent signal of the flourophor during the RNase H-mediated reaction.
16. A method of screening for a modulator of the nuclease activity of an agent, which method comprises:
(a) hybridizing a target nucleic acid to a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor;
(b) preparing two samples containing the probe-target hybrid;
(c) contacting the probe-target hybrid of a first sample with the agent in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe;
(d) contacting the probe-target hybrid of a second sample with the agent in an amount sufficient to selectively cleave the target nucleic acid and thereby release the intact probe in the presence of a candidate compound, which is being tested for its ability to modulate the nuclease activity of the agent;
(e) detecting the release of the probe in each sample by measuring a decrease in the flourescent signal of the flourophor as compared to the signal of the probe-target hybrid; and
(f) comparing the rate of the decrease in the flourescent signal of the flourophor in the two samples, wherein a difference in the rate of the decrease in the flourescent signal of the flourophor during the nuclease reaction in the two samples is indicative of the ability of the compound to either inhibit or enhance the nuclease activity of the agent.
17. The method of claim 16, wherein a greater extent or relative rate of decrease of the flourescent signal of the flourophor in the second sample compared to the first sample indicates that the candidate compound is an agent agonist.
18. The method of claim 16, wherein a lesser extent or relative rate of decrease of the flourescent signal of the flourophor in the second sample compared to the first sample indicates that the candidate compound is an agent antagonist.
19. A kit for measuring a nuclease activity of an agent, comprising a target nucleic acid and a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quencher at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor.
20. The kit of claim 19, wherein the probe is at least 18 nucleotides in length.
21. The kit of claim 19, wherein the probe, when unhybridized to the target nucleic acid, adopts a hairpin secondary structure conformation that brings the fluorophor and quencher into proximity.
22. The kit of claim 19, wherein the probe is DNA, and the target nucleic acid is DNA:RNA hybrid substrate.
23. The kit of claim 19, further comprising the agent.
24. The kit of claim 23, wherein the agent is is selected from the group consisting of RNase H, reverse transcriptase, E. coli RNase H1 and H2, Human RNase H1 and H2, hammerhead ribozymes, HBV reverse transcriptase, and integrase.
25. The kit of claim 23, wherein the reverse transcriptase is HIV reverse transcriptase.
26. An assay mixture for measuring a nuclease activity of an agent, comprising a target nucleic acid and a fluorescently labeled oligonucleotide probe complementary to the target nucleic acid and containing a flourophor at one terminus and a quenching group at the other terminus, wherein (i) when the probe is unhybridized to the target nucleic acid, the probe adopts a conformation that places the flourophor and quencher in such proximity that the quencher quenches the flourescent signal of the flourophor and (ii) formation of the probe-target hybrid causes sufficient separation of the flourophor and quencher to reduce quenching of the flourescent signal of the flourophor.
27. The assay mixture of claim 26, wherein the probe is DNA, and the target nucleic acid is RNA.
28. The assay mixture of claim 26, wherein the probe and the target nucleic acid are hybridized to each other to form a probe-target hybrid.
29. The assay mixture of claim 28, further comprising the agent.
30. The assay mixture of claim 29, wherein the agent is selected from the group consisting of RNase H, reverse transcriptase, E. coli RNase H1 and H2, Human RNase H1 and H2, hammerhead ribozymes, HBV reverse transcriptase, and integrase.
31. The assay mixture of claim 30, wherein the reverse transcriptase is HIV reverse transcriptase.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. An output control method for a consumable electrode arc welding power source in which an output of the welding power source is controlled based on an amplified error value between a predetermined voltage setting value and a welding voltage,
wherein an entire application range of a welding current is segmentalized into a plurality of current zones, a norm welding voltage value is set for each of the current zones, a welding current and a welding voltage are detected at each of minute cycles, one of the current zones which corresponds to a value of the detected welding current is selected, a fluctuation range is calculated with the norm welding voltage value of the selected current zone as a center value, a welding voltage limit value is calculated while the detected value of the welding voltage is limited to within the fluctuation range, and the amplified error value is calculated using the voltage setting value and the welding voltage limit value.
2. The method according to claim 1, wherein a moving average of the welding voltage limit values is obtained for each of the current zones for the calculation of the norm welding voltage value for each of the current zones.
3. An output control method for a consumable electrode arc welding power source in which an output of a welding power source is controlled based on an amplified error value between a predetermined voltage setting value and a welding voltage,
wherein a norm characteristic of an arc characteristic curve which indicates a relation between a welding current and a welding voltage during arc generation is set, a welding current and a welding voltage are detected at each of minute cycles, a norm welding voltage value which corresponds to a detected value of the welding current is calculated on the norm characteristic, a fluctuation range is calculated with the norm welding voltage value as a center value, a welding voltage limit value is calculated while the detected value of the welding voltage is limited to within the fluctuation range, and the amplified error value is calculated using the voltage setting value and the welding voltage limit value.
4. The method according to claim 3, wherein an approximating curve is calculated for each of predetermined calculation cycles while welding is performed using operational points data constituted from the detected value of the welding current and the corresponding welding voltage limit value in each of the minute cycles, and the approximating curve is set as the norm characteristic.
5. The method according to claim 1, wherein an output voltage which is a voltage at a point on a output path in the welding power source before the reactor mounted on the output path is detected, a deviation between the detected value of the welding voltage and the welding voltage limit value is calculated, a voltage control setting value is calculated by adding the deviation to the voltage setting value, and the amplified error value is calculated using the voltage control setting value and the detected value of the output voltage.
6. The method according to claim 1, wherein each of the norm welding voltage values in all of the current zones is modified based on a change amount of the voltage setting value in the case that the voltage setting value changes.
7. The method according to claim 3, wherein the norm characteristic is modified toward a direction of a welding voltage axis based on a change amount of the voltage setting value in the case that the voltage setting value changes.
8. The method according to claim 3, wherein the norm characteristic is set differently for a plurality of potions to be welded.