1. A variable RC oscillator, comprising:
(a) an RC selecting switch disposed in an input port of the oscillator;
(b) a resistor output port;
(c) a capacitor output port;
(d) at least a resistor switch with a first end connected to the RC selecting switch and a second end floatingly connected to the resistor output port; and
(e) at least a capacitor switch with a first end connected to the RC selecting switch and a second end floatingly connected to the capacitor output port,
wherein the second ends of the resistor switch and the capacitor switch are selectively connected to the resistor output port and the capacitor output port respectively for providing different combinations of a resistor output value and a capacitor output value.
2. The variable RC oscillator according to claim 1, wherein the oscillator is a single-channel variable RC oscillator.
3. The variable RC oscillator according to claim 1, wherein a selection control of the resistor switch and the capacitor switch electrically connected to the ROUT and COUT, respectively, determined by the RC selecting switch is implemented by an external control of the oscillator.
4. The variable RC oscillator according to claim 1, wherein the resistor output port and the capacitor output port are electrically connected to different fixed DC voltage levels, respectively.
5. The variable RC oscillator according to claim 1, wherein the resistor output port and the capacitor output port are electrically connected to an output port of the oscillator.
6. The variable RC oscillator according to claim 1, further comprising:
A plurality of enable switches connected between the RC selecting switch and the resistor switch, and between the RC selecting switch and the capacitor switch, in order to respond at least one enable signal generated by the RC selecting switch for selectively connecting the resistor switch with the resistor output port and the capacitor switch with the capacitor output port.
7. The variable RC oscillator according to claim 1, further comprising m resistor switches and n capacitor switches, wherein m and n are integers greater than one, and m plus n is equal to a bit number of the oscillator.
8. A micro controller unit (MCU), comprising at least a variable RC oscillator according to claim 1.
9. A variable RC oscillator, comprising:
(a) an RC selecting switch disposed in an input of the oscillator;
(b) a plurality of resistor switches, each of which having a first end connected to the RC selecting switch and a second end floatingly connected to a resistor output of the oscillator; and
(c) a plurality of capacitor switches, each of which having a first end connected to the RC selecting switch and a second end floatingly connected to a capacitor output of the oscillator,
wherein each of the second ends of the plurality of resistor switches and each of the second ends of the plurality of capacitor switches are selectively connected to the resistor output and the capacitor output, respectively.
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 method of differentiating adipose stromal cells into osteoblasts, comprising: culturing said cells in a composition comprising a medium capable of supporting the growth of fibroblasts and differentiation inducing amounts of -glycerophosphate and ascorbic acid andor ascorbic-2 phosphate.
2) The method of claim 1, wherein said amounts are about 2-20 mM -glycerophosphate and about 20-75 M ascorbic acid andor ascorbic-2 phosphate.
3) The method of claim 2 wherein said amounts are about 5-15 M -glycerophosphate and about 40-60 M ascorbic acid andor ascorbic-2 phosphate.
4) The method of claim 3, wherein said amounts are about 10 mM -glycerophosphate and about 50 M ascorbic acid andor ascorbic-2 phosphate.
5) The method of claim 1, wherein said medium is selected from the group consisting of: DMEM, MEM and BME.
6) The method of claim 1, wherein said medium further comprises about 5-20% fetal calf serum.
7) The method of claim 1, wherein said medium further comprises one or more bone morphogenetic proteins.
8) The method of claim 1 wherein said cells are mammalian.
9) The method of claim 8 wherein said cells are human.
10) A method of identifying compounds that affect osteoblast differentiation, comprising:
a) culturing adipose stromal cells in the presence and absence of a compound to be tested for effect on osteoblast differentiation in a composition which comprises a medium capable of supporting the growth of fibroblasts and differentiation inducing amounts of -glycerophosphate and ascorbic acid andor ascorbic-2 phosphate; and
b) comparing osteoblast differentiation in said cells cultured in the presence of said compound to that of said cells cultured in the absence of said compound.
11) The method of claim 10, wherein said amounts are about 2-20 mM -glycerophosphate and about 20-75 M ascorbic acid andor ascorbic-2 phosphate.
12) The method of claim 11, wherein said amounts are about 5-15 mM -glycerophosphate and about 40-60 M ascorbic acid andor ascorbic-2 phosphate.
13) The method of claim 12, wherein said amounts are about 10 mM -glycerophosphate and about 50 M ascorbic acid andor ascorbic-2 phosphate.
14) A method of improving a subject’s bone structure, comprising:
a) culturing adipose stromal cells in a composition which comprises a medium capable of supporting the growth of fibroblasts and differentiation inducing amounts of -glycerophosphate and ascorbic acid andor ascorbic-2 phosphate; and
b) introducing said osteoblasts into a surgery or fracture site of said subject.
15) The method of claim 14, wherein said amounts are about 2-20 mM -glycerophosphate and about 20-75 M ascorbic acid andor ascorbic-2 phosphate.
16) The method of claim 15, wherein said amounts are about 5-15 mM -glycerophosphate and about 40-60 M ascorbic acid andor ascorbic-2 phosphate.
17) The method of claim 16, wherein said amounts are about 10 mM -glycerophosphate and about 50 M ascorbic acid andor ascorbic-2 phosphate.
18) The method of claim 14, wherein said adipose stromal cells are isolated from said subject.
19) The method of claim 14, wherein said medium is selected from the group consisting of: DMEM, MEM and BME.
20) The method of claim 14, wherein said medium further comprises about 5-20% fetal calf serum.
21) The method of claim 14, wherein said medium further comprises one or more bone morphogenetic proteins.
22) The method of claim 14, wherein said subject is mammalian.
23) The method of claim 22, wherein said subject is human.
24) The method of claim 14, wherein said osteoblasts are introduced in admixture with a composition useful in the repair of bone wounds, bone defects andor bone disorders.
25) The method of claim 14, wherein a nucleotide sequence of interest is introduced into said adipose stromal cells or said osteoblasts.
26) A composition comprising adipose stromal cells, a medium capable of supporting the growth of fibroblasts and amounts of -glycerophosphate and ascorbic acid andor ascorbic-2 phosphate sufficient to induce the differentiation of said stromal cells into osteoblasts.
27) The composition of claim 26, wherein said amounts are about 2-20 mM -glycerophosphate and about 20-75 M ascorbic acid andor ascorbic-2 phosphate.
28) The composition of claim 27, wherein said amounts are about 5-15 mM -glycerophosphate and about 40-60 M ascorbic acid andor ascorbic-2 phosphate.
29) The composition of claim 28, wherein said amounts are about 10 mM -glycerophosphate and about 50 M ascorbic acid andor ascorbic-2 phosphate.
30) The composition of claim 26, wherein said stromal cells are human.