Process and device characterization for a 30-GHz fT submicrometer double poly-Si bipolar technology using BF2-implanted base with rapid thermal process

Process and device parameters are characterized in detail for a 30-GHz f_T submicrometer double poly-Si bipolar technology using a BF₂-implanted base with a rapid thermal annealing (RTA) process. Temperature ramping during the emitter poly-Si film deposition process minimizes interfacial oxide film growth. An emitter RTA process at 1050°C for 30 s is required to achieve an acceptable emitter-base junction leakage current with an emitter resistance of 6.7×10^-7 Ω-cm², while achieving an emitter junction depth of 50 nm with a base width of 82 nm. The primary transistor parameters and the tradeoffs between cutoff frequency and collector-to-emitter breakdown voltage are characterized as functions of base implant dose, pedestal collector implant dose, link-base implant dose, and epitaxial-layer thickness. Transistor geometry dependences of device characteristics are also studied. Based on the characterization results for poly-Si resistors, boron-doped p-type poly-Si resistors show significantly better performance in temperature coefficient and linearity than arsenic-doped n-type poly-Si resistors     

Family involvement in school and low-income children's literacy: Longitudinal associations between and within families.

Longitudinal data from kindergarten to 5th grade on both family involvement in school and children's literacy performance were examined for an ethnically diverse, low-income sample (N = 281). Within families, increased school involvement predicted improved child literacy. In addition, although there was an achievement gap in average literacy performance between children of more and less educated mothers if family involvement levels were low, this gap was nonexistent if family involvement levels were high. These results add to existing evidence on the value of family involvement in school by demonstrating that increased involvement between kindergarten and 5th grade is associated with increased literacy performance and that high levels of school involvement may have added reward for low-income children with the added risk of low parent education. As such, these results support arguments that family involvement in school should be a central aim of practice and policy solutions to the achievement gap between lower and higher income children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mediational role of adolescents' friends in relations between activity breadth and adjustment.

This investigation addresses the mediational role of friends' characteristics between adolescents' activity breadth (i.e., variety in activity participation) and their later adjustment. Data were drawn from 2 longitudinal studies: the Childhood and Beyond (CAB; N = 925) study and the Maryland Adolescent Development in Context Study (MADICS; N = 1,338). Adolescents at Time 2 in each study (8th, 9th, and 11th graders in CAB and 8th graders in MADICS) reported on the breadth of their participation across 5 activity settings: sports, religious, volunteering, community, and school. Friends' characteristics and adolescent adjustment were reported by adolescents at Times 1 and 3. Friends' positive characteristics significantly mediated relations between activity breadth and adolescent depressive affect, self-worth, alcohol use, and problem behavior in both studies. Friends' negative characteristics significantly mediated these relations in CAB, but not in MADICS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vasopeptidase inhibitors: incorporation of geminal and spirocyclic substituted azepinones in mercaptoacyl dipeptides

A series of 7-(di)alkyl and spirocyclic substituted azepinones were generated and incorporated as conformationally restricted dipeptide surrogates in mercaptoacyl dipeptides. Clear structure-activity relationships with respect to both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) activity in vitro were observed. The best in this series, compound 1g, a geminally dimethylated C-7-substituted azepinone, demonstrated excellent blood pressure lowering in animal models. Compound 1g (BMS-189921) is characterized by a good duration of activity and excellent oral efficacy in models relevant to ACE or NEP inhibition, and its activity is comparable to that of the clinically efficacious agent omapatrilat. Consequently this inhibitor has been advanced clinically for the treatment of hypertension and congestive heart failure.     

Testosterone increases and estradiol decreases middle cerebral artery occlusion lesion size in male rats

This study was undertaken to determine the effects of estrogen and testosterone on cerebral ischemic lesion size induced by middle cerebral artery (MCA) occlusion in male rats. Rats were gonadectomized and treated with testosterone, estrogen, or testosterone plus estrogen filled Silastic pellets. The animals were divided into 6 groups: intact, intact + estrogen (E2), castrate, castrate + testosterone (T), castrate + E2, and castrate + T + E2. One week after treatment, cerebral ischemia was induced by MCA occlusion for 40 min, followed by reperfusion. After 24 h, rats were sacrificed and slices were then stained to assess lesion size. The presence of testosterone increased and the removal of testosterone decreased lesion size. A strong positive correlation (r2 = 0.922) between plasma testosterone concentrations and ischemic lesion size was observed. Estradiol treatment reduced ischemic area. In summary, the present study provides evidence that testosterone exacerbates and estrogens ameliorate ischemic brain damage in an animal model of cerebral ischemia.     

The temporal interaction of corticosterone and prolactin in affecting liver lipid metabolism of the chick

Experiments were conducted to determine if Brown Leghorn chickens (Gallus domesticus) showed a daily differential responsiveness to the phased injections of corticosterone and prolactin. In experiment 1, 28 day old chicks, maintained on continuous lighting and a standard diet, were treated daily for 6 days with corticosterone (300 mug. in 0.2 cc. saline) and with prolactin (150 mug. in 0.2 cc. saline) for 4 days. The prolactin injections began 2 days after the first corticosterone injection. The interval between daily corticosterone injections at 1800 hours followed by prolactin injections 6, 12 or 18 hours later resulted in a significant increase in the liver lipidcontent in the chicks. However, when corticosterone and prolactin were given at the same time (1800 hours), no increase in liver lipid content was observed. Corticosterone admininstered at 6oo hours and followed by prolactin injections had no effect on liver lipid content regardless of the time of prolactin prolactin injections. Experiment 2 was designed to test the effect of the administration of corticosterone or prolactin alone at either 600 hours or 1800 hours on liver lipid metabolism. Two groups of Brown Leghorn chicks received prolactin alone (for 2 days) at either 600 hours or 1800 hours. None of these treatment groups were significantly different from the uninjected controls. It is concluded that the chick has a diurnal sensitivity to the effects of coritcosterone and that once the liver is affected by corticosterone, a temporal interaction between this steroid and prolactin can affect the liver lipid content of the Brown Leghorn chick.