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31.
A MOSFET structure with a nonoverlapped source/drain (S/D) to gate region was proposed to overcome the challenges in sub-50-nm CMOS devices. Key device characteristics were investigated by extensive simulation study. Fringing gate electric field through the spacer induces an inversion layer in the nonoverlap region to act as an extended S/D region. An oxide spacer is used to reduce parasitic gate overlap capacitance. A reasonable amount of inversion electrons were induced under the spacers. Internal physics, speed characteristics, short channel effects, and RF characteristics were studied with the nonoverlap distance at a fixed metallurgical channel length of 40 nm. The proposed structure had good drain-induced barrier lowering and V/sub T/ rolloff characteristics and showed reasonable intrinsic gate delay and cutoff frequency compared to those of an overlapped structure.  相似文献   
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CONTEXT: An increase in the recreational use of personal watercraft (PWC) raises concern about an increase in associated injuries on a national level. OBJECTIVE: To estimate the relative frequency, types of injury, and demographic features of persons injured while using PWC in the United States. DESIGN: Case series. SETTING: Emergency department (ED) visits to hospitals participating a national probability sample. PARTICIPANTS: All persons treated for PWC-related injury from January 1,1990, through December 31, 1995. RESULTS: An estimated 32954 persons (95% confidence interval [CI], 22919-42989) with PWC-related injuries were treated in US hospital EDs, of which 3.5% were hospitalized. Personal watercraft-related injuries have increased significantly from an estimated 2860 in 1990 to more than 12000 in 1995. During this period, the number of PWC in operation increased 3-fold from approximately 241500 in 1990 to an estimated 760000 in 1995. The most prevalent diagnoses were lacerations, contusions, and fractures. MAIN OUTCOME MEASURES: The estimated number and percentage of patients treated in EDs for PWC-related injuries, by year, age, sex, and the number and rate per 1000 of PWC in operation by year. CONCLUSIONS: Since 1990, there has been at least a 4-fold increase in injuries associated with an increase in the recreational use of PWC. The rate of ED-treated injuries related to PWC was about 8.5 times higher (95% CI, 8.2-8.8; 1992 data) than the rate of those from motorboats. Specific training and adult supervision is recommended for minors using PWC. Furthermore, medical practitioners should encourage personal flotation device use and other protection for their patients who are known water enthusiasts.  相似文献   
35.
A logic language is suitable for specification if it is equipped with features for data abstraction and modularization. In this paper, an effective mechanism to incorporate function and type into logic programming is presented as the means to embed data abstraction mechanism into logic programming. This incorporation is essentially based on Horn clause logic with equality and a polymorphic type system that is an extension of Mycroft and O’Keefe’s system. This paper also presents an implementation based on Warren Abstract Machine (WAM) and shows the performance, along with a comparison with WAM.  相似文献   
36.
A series of polyurethane block copolymers based on hydroxy-terminated polydimethylsiloxane and poly(propylene glycol) soft segments of molecular weights 1818 and 2000, respectively, were synthesized. The hard segments consisted of 4,4′-diphenylnethane diisocyanate and 1,4-butanediol as the chain extender. Samples with different molar ratios were prepared. We tried to synthesize polydimethylsiloxane-based polyurethanes (PDMS-PU) containing a hard block as major fraction and a soft block as minor fraction for preparing toughened rigid systems. After a study of the pure polydimethylsiloxane-based polyurethane and poly(propylene glycol)-based polyurethane (PPG-PU), (mixed polyol)-based block copolymers and blends of PDMS-PU and PPG-PU were synthesized, and characterized by means of differential scanning calorimetry, tensile testing and scanning electron microscopy. In (mixed polyol)-based copolymers and lower hard-segment content blends, macro-phase separation occurred, but blends with higher hard-segment contents showed significant reduction in amounts of phase separation.  相似文献   
37.
BACKGROUND: Cisplatin-based combination chemotherapy will cure 70% to 80% of patients with metastatic non-seminomatous germ cell tumors but is associated with the possibility of severe neuro-, oto- and nephro-toxicities. Carboplatin, a cisplatin analogue, is an active drug in testicular cancer with a more favourable spectrum of side effects. In a randomized trial, the German Testicular Cancer Study Group compared a combination regimen of carboplatin, etoposide and bleomycin (CEB) to standard cisplatin, etoposide and bleomycin (PEB) chemotherapy for patients with 'minimal-' and moderate-disease' non-seminomatous germ cell tumors, according to the Indiana University classification. PATIENTS AND METHODS: PEB was given for three cycles at standard doses (given days 1-5), and the CEB regimen consisted of carboplatin (target AUC of 5 mg/ml x min) on day 1, etoposide 120 mg/m2 on days 1 to 3 and bleomycin 30 mg on days 1, 8 and 15. Four cycles of CEB were given, with the omission of bleomycin in the fourth cycle. Thus, the cumulative doses of etoposide and bleomycin applied in the two treatment arms were comparable. Fifty-four patients were entered on the trial, 29 were treated with PEB and 25 with CEB chemotherapy. Patients were stratified according to disease extent (minimal versus moderate) and the degree of tumor marker elevation. Thirty-two patients (59%) belonged to the group with minimal disease and low markers. RESULTS: No significant difference in response to chemotherapy was seen between the two arms, with CR rates of 81% for the PEB arm and 76% for CEB treatment. However, more patients treated with CEB (32% versus 13%) have relapsed after therapy, and 4 patients (16%) have died of disease progression after CEP in contrast to 1 (3%) after PEB therapy. The first interim analysis of negative events (relapse, vital tumor at secondary resection, death from disease and therapy-associated death) showed a significantly higher rate after CEB than after PEB therapy, and the trial was terminated early. After a median follow-up of 33 months for all patients, the calculation of negative events is still significantly in favour of PEB-treated patient, particularly since three late relapses > 2 years have been observed in the CEB arm (P = 0.03). CONCLUSION: This randomized trial demonstrates that even with the use of adequate doses of etoposide and full-dose bleomycin, carboplatin cannot altogether replace cisplatin in patients with testicular cancer. Treatment with the PEB regimen remains the standard approach in patients with 'good-risk' non-seminomatous germ cell tumors.  相似文献   
38.
A two-dimensional finite element model was constructed to analyze the simulated mechanical behavior of a cantilevered fixed partial denture. The variations of the models were made by altering the degree of bone support, the number of splinted abutments, and the length of the pontics. High stress concentrations were observed around the connectors of the fixed prosthesis and the tooth closest to the cantilever. Reduced bone support increased the deflection and stress concentrations. There was reduction in displacement and stress concentration when the teeth were splinted together. To improve the prognosis of the fixed partial denture cantilever, the number of abutments should be increased and the number of pontics decreased.  相似文献   
39.
A model of induced lactation was modified to examine the effects of bovine prolactin (bPRL) and bovine placental lactogen (bPL) on mammary growth and differentiation. Thirty-two peripubertal, non-pregnant Holstein heifers were given daily s.c. injections of oestradiol (0.05 mg/kg) and progesterone (0.25 mg/kg) for 7 days to initiate mammary growth. Treatment with bromocriptine (40 mg/3 days) reduced serum PRL concentrations to approximately 25% of pretreatment levels, for the duration of the study. On the day following the last steroid injection, groups of eight heifers were given twice daily s.c. injections of either saline (negative control), recombinant bPRL (rbPRL; 80 mg/day) or recombinant bPL (rbPL; 80 and 160 mg/day) for 7 days. At the end of this period (day 15), growth and differentiation of the mammary glands were assessed. Treatment with rbPL increased total mammary DNA above control value by 50 and 60% for the 80 and 160 mg/day doses respectively. However, total DNA was not different for the control and rbPRL-treated groups. The blood serum concentration of alpha-lactalbumin was measured daily throughout the study and used as an index of mammary differentiation. Both rbPRL and rbPL stimulated mammary differentiation (i.e. induction of milk synthesis), although rbPRL appeared to be more potent than rbPL. These results indicate that rbPL is lactogenic in vivo and strongly suggest that bPL is a mammary mitogen.  相似文献   
40.
The pyrolytic behavior of inulin, a (2-->1)-linked fructofuranan, is described. Parallel investigations of the pyrolysis of glucose and of fructose were conducted to supplement the inulin results and to aid comparison with previous results from glucans. Effects of neutral and basic additives are emphasized. As with glucans, the addition of such additives (especially basic) increases the yields of the one-, two-, and three-carbon products (as well as of hexosaccharinolactones), while generally decreasing the yields of anhydro sugar and furan derivatives. The former products include glycolaldehyde, acetol, dihydroxy-acetone, acetic acid, formic acid, and lactic acid. Mechanistic speculations are made regarding the origins of these compounds, as well as of furan derivatives and saccharinic acid lactones. Parallels with alkaline degradation are considered.  相似文献   
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