536 research outputs found
Laser Field Induced Birefringence and Enhancement of Magneto-optical Rotation
An initially isotropic medium, when subjected to either a magnetic field or a
coherent field, can induce anisotropy in the medium and can cause the
polarization of a probe field to rotate. Therefore the rotation of probe
polarization, due to magnetic field alone, can be controlled efficiently with
the use of a coherent control field. We demonstrate this enhancement of the
magneto-optical rotation (MOR) of a linearly polarized light, by doing detailed
calculations on a system with relevant transitions .Comment: 9 pages including 4 Figure
Measurement of surface roughness by a fiber-optic transducer.
Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1982 .A437. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.Sc.)--University of Windsor (Canada), 1982
Minimally invasive versus the conventional open surgical approach of a radical cholecystectomy for gallbladder cancer: a retrospective comparative study
AbstractBackgroundLaparoscopic surgery has traditionally been contraindicated for the management of gall bladder cancer (GBC). This study was undertaken to determine the safety and feasibility of a laparoscopic radical cholecystectomy (LRC) for GBC and compare it with an open radical cholecystectomy (ORC).MethodsRetrospective analysis of primary GBC patients (with limited liver infiltration) and incidental GBC (IGBC) patients (detected after a laparoscopic cholecystectomy) who underwent LRC between June 2011 and October 2013. Patients who fulfilled the study criteria and underwent ORC during the same period formed the control group.ResultsDuring the study period, 147 patients with GBC underwent a radical cholecystectomy. Of these, 24 patients (primary GBC– 20, IGBC – 4) who underwent a LRC formed the study group (Group A). Of the remaining 123 patients who underwent ORC, 46 matched patients formed the control group (Group B). The median operating time was higher in Group A (270 versus 240 mins, P= 0.021) and the median blood loss (ml) was lower (200 versus 275 ml, P= 0.034). The post-operative morbidity and mortality were similar (P= 1.0). The pathological stage of the tumour in Group A was T1b (n = 1), T2 (n = 11) and T3 (n = 8), respectively. The median lymph node yield was 10 (4–31) and was comparable between the two groups (P=0.642). During a median follow-up of 18 (6–34) months, 1 patient in Group A and 3 in Group B developed recurrence. No patient developed a recurrence at a port site.ConclusionLRC is safe and feasible in selected patients with GBC, and the results were comparable to ORC in this retrospective comparison
Spontaneously generated atomic entanglement in free space: reinforced by incoherent pumping
We study spontaneously generated entanglement (SGE) between two identical
multilevel atoms in free space via vacuum-induced radiative coupling. We show
that the SGE in two-atom systems may initially increase with time but
eventually vanishes in the time scale determined by the excited state lifetime
and radiative coupling strength between the two atoms. We demonstrate that a
steady-state SGE can be established by incoherently pumping the excited states
of the two-atom system. We have shown that an appropriate rate of incoherent
pump can help producing optimal SGE. The multilevel systems offer us more
chanel to establish entanglement. The system under consideration could be
realized in a tight trap or atoms/ions doped in a solid substrate.Comment: have some difference with published version (please see PRA
Synthesis, antiviral and contraceptive activities of nucleoside–sodium cellulose sulfate acetate and succinate conjugates
Chemical conjugates between sodium cellulose sulfate (CS), displaying contraceptive and HIV-entry inhibiting properties, and nucleoside reverse transcriptase inhibitors (NRTIs) (3′-azido-2′,3′-dideoxythymidine (AZT), 3′-fluoro-2′,3′-dideoxythymidine (FLT), or 2′,3′-dideoxy-3′-thiacytidine (3TC)) were designed to simultaneously provide contraceptive and anti-HIV activity. Two linkers, acetate and succinate, were used to conjugate the nucleoside analogs with CS. The conjugates containing cellulose sulfate-acetate (CSA) (e.g., AZT–CSA and FLT–CSA) were found to be more potent than CS and other conjugates (e.g., AZT–succinate–CS, and FLT–succinate–CS). The presence of both sulfate and the acetate groups on cellulose were critical for generating maximum anti-HIV activity. In addition to showing equal potency against wild-type and multidrug resistant HIV-1, the AZT–CSA conjugate displayed significant contraceptive activity in an animal model, providing the initial proof-of-concept for the design and synthesis of dual-activity compounds based on these combinations.
[Refer to PDF for graphical abstract
Alzheimer’s Disease: A Challenge In The Face Of Modern Era
Alzheimer’s disease (AD) is a devastating disease which affects the mental capacity and hence the standard of life of patients suffering from this disease. The accumulation of β-amyloid plaques and tau tangles has been found to be central to the disease. Over the years, research on β-secretase has become known as a hopeful target for the exploration of AD. A number of drugs have been approved by the US-FDA which meliorates only some of the symptoms of AD, but do not help in modifing the principal disease mechanisms
Synthesis and in Vitro Characterization of Novel Dextran–Methylprednisolone Conjugates with Peptide Linkers: Effects of Linker Length on Hydrolytic and Enzymatic Release of Methylprednisolone and its Peptidyl Intermediates
To control the rate of release of methylprednisolone (MP) in lysosomes, new dextran–MP conjugates with peptide linkers were synthesized and characterized. Methylprednisolone succinate (MPS) was attached to dextran 25 kDa using linkers with 1–5 Gly residues. The release characteristics of the conjugates in pH 4.0 and 7.4 buffers, blood, liver lysosomes, and various lysosomal proteinases were determined using a size-exclusion and/or a newly developed reversed-phase HPLC method capable of simultaneous quantitation of MP, MPS, and all five possible MPS-peptidyl intermediates. We synthesized conjugates with ≥90% purity and 6.9–9.5% (w/w) degree of MP substitution. The conjugates were stable at pH 4.0, but released MP and intact MPS-peptidyl intermediates in the pH 7.4 buffer and rat blood, with faster degradation rates for longer linkers. Rat lysosomal fractions degraded the conjugates to MP and all the possible intermediates also at a rate directly proportional to the length of the peptide. Whereas the degradation of the conjugates by cysteine peptidases (papain or cathepsin B) was relatively substantial, no degradation was observed in the presence of aspartic (cathepsin D) or serine (trypsin) proteinases, which do not cleave peptide bonds with Gly. These newly developed dextran conjugates of MP show promise for controlled delivery of MP in lysosomes
Role of male behavior in cervical carcinogenesis among women with one lifetime sexual partner
Background: The role of male behavior in the genesis of cervical cancer was examined. In India, where the incidence of cervical cancer is among the highest in the world, promiscuity among women is virtually unknown. In this study, the authors investigated the role of male behavior in cervical carcinogenesis among Indian women who had one lifetime sexual partner. Methods: A case-control study was used. Results. Premarital sexual relationships (relative risk [RR], 1.9; confidence interval, 1.2-3.2) and extramarital sexual relationships (RR, 2.7; confidence interval, 1.5-4.9) of husbands were risk factors. When husbands had sexual relationships both before and during the marriage, their wives' risk of getting cervical cancer increased by 6.9 (CI, 2.3-20.7). Risk also increased with husbands having three or more extramarital sexual partners (RR, 3.05; CI, 1.25-12.6). Sexual contact with prostitutes before or after marriage, however, did not increase the risk. History of sexually transmitted disease before marriage (RR, 2.9) or after marriage (RR, 5.9) was an important risk factor, which persisted after controlling for other factors. Sexual abstinence for 40 or more days after a wife's giving birth or having an abortion provided protection. Sex with uncircumcised men or men circumcised after age 1 year increased the risk of cervical cancer (RR, 4.1). Bidi smoking (bidi is a cheap smoking stick of 4-8 cm, consisting of a rolled piece of dried temburni leaf [Diospyres melanoxylon] containing 0.15-0.25 g of coarsely ground tobacco) for more than 20 years was a significant risk factor (RR = 2.4), whereas cigarette smoking was not a risk factor. Conclusions: Male sexual partners play a role in cervical carcinogenesis
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