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91.
Mark E. Barnes Geoff J. Daniell Paul Gow Vasilis Apostolopoulos 《Journal of Infrared, Millimeter and Terahertz Waves》2014,35(12):1030-1044
In this paper we model the carrier dynamics and resulting THz emission from lateral diffusion currents within a semiconductor device which has been partially masked by a metallic mask. We present a numerical 1D model and a 1D Monte Carlo simulation which both demonstrate that regardless of the excitation laser spot shape we do not expect to see measurable THz emission in the direction of the optical pump propagation from lateral diffusion currents. Experimentally such devices do produce strong THz emission. We analytically investigate the role of the metal mask and we found that it suppresses the emission of dipoles that are in a region that is less than a wavelength away from the interface. The results from the numerical model are also included in a finite element analysis model of the geometry which predicts THz emission if and only if the metal mask is present. 相似文献
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As the proportion of older people continues to increase there will be a greater need to provide support and care more efficiently. CAREnet proactively supports older people in their own homes by recording patterns of behaviour using distributed sensors. Telephone help messages can be sent to a carer should an unusual activity pattern be detected. 相似文献
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Purification and crystallization of complexes modeling the active state of the fragile histidine triad protein 总被引:1,自引:0,他引:1
Brenner C; Pace HC; Garrison PN; Robinson AK; Rosler A; Liu XH; Blackburn GM; Croce CM; Huebner K; Barnes LD 《Protein engineering, design & selection : PEDS》1997,10(12):1461-1463
Fragile histidine triad protein (Fhit) is a diadenosine triphosphate
(ApppA) hydrolase encoded at the human chromosome 3 fragile site which is
frequently disrupted in tumors. Reintroduction of FHIT coding sequences to
cancer cell lines with FHIT deletions suppressed the ability of these cell
lines to form tumors in nude mice even when the reintroduced FHIT gene had
been mutated to allow ApppA binding but not hydrolysis. Because this
suggested that the tumor suppressor activity of Fhit protein depends on
substrate-dependent signaling rather than ApppA catabolism, we prepared two
crystalline forms of Fhit protein that are expected to model its
biologically active, substrate-bound state. Wild-type and the His96Asn
forms of Fhit were overexpressed in Escherichia coli, purified to
homogeneity and crystallized in the presence and absence of ApppA and an
ApppA analog. Single crystals obtained by vapor diffusion against ammonium
sulfate diffracted X-rays to beyond 2.75 A resolution. High quality native
synchrotron X-ray data were collected for an orthorhombic and a hexagonal
crystal form.
相似文献
97.
RB Barnes 《Canadian Metallurgical Quarterly》1997,11(2):369-396
Diagnostic categories in hyperandrogenism include polycystic ovary syndrome (PCOS) and its variants, adrenal and ovarian steroidogenic enzyme deficiencies, adrenal and ovarian androgen secreting tumours and other endocrine disorders such as hyperprolactinaemia, Cushing syndrome and acromegaly. About 95% of hyperandrogenic women will have PCOS. Endometrial hyperplasia can be prevented in hyperandrogenic, anovulatory women by the oral contraceptive pill or progestins. Hirsutism is best treated by a combination of the oral contraceptive pill and an anti-androgen. The first line of therapy for ovulation induction is clomiphene citrate, with human menopausal gonadotrophins (hMG) or laparoscopic ovulation induction reserved for clomiphene failures. hMG together with gonadotrophin-releasing hormone agonist may decrease the risk of spontaneous abortion following ovulation induction in PCOS. Weight loss should be vigorously encouraged to ameliorate the metabolic consequences of PCOS. 相似文献
98.
RP Abratt GL McAdam AR Pontin RD Barnes HS Ball 《Canadian Metallurgical Quarterly》1997,35(4):203-5; discussion 205-6
To evaluate the efficacy and toxicity of primary chemotherapy in patients with stage 2 (retroperitoneal lymph node metastases) testis cancer, 20 consecutive patients referred to Groote Schuur Hospital between September 1992 and March 1994 were reviewed. There were 10 patients with non-bulky non-seminomatous germ cell tumour (NSGCT), 5 with bulky NSGCT and 5 with bulky seminoma. The treatment regimen consisted initially of 4 cycles of cisplatin, etoposide and bleomycin. Patients with NSGCT and a residual mass after chemotherapy subsequently underwent retroperitoneal lymph node dissection (RPLND) and those with seminoma underwent a low dose of irradiation to the mass. In 7 (70%) of the 10 patients with non-bulky NSGCT, there was a complete response to chemotherapy and 3 patients underwent limited RPLND. One patient relapsed at follow-up but remains clear of disease after salvage therapy. The survival rate is 100% at a median follow-up of 60 months (range 12-143 months). In 5 patients with bulky NSGCT there was no complete response to chemotherapy. Three have undergone limited RPLND. The survival rate is 52% at a median follow-up of 130 months (range 108-152 months). In 5 patients with bulky seminomas, the survival rate is 100% at a median follow-up of 55 months (range 29-92 months). Toxicity has been modest except for 1 patient who died postoperatively in the early part of the study. Four patients have fathered children after treatment. We conclude that primary chemotherapy is the treatment of choice for patients with stage 2 testis cancer. 相似文献
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