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91.
Armed conflict affects the biological diversity and biological research regime of a country. This paper takes a low-intensity armed conflict in the biologically and ethnically diverse Chittagong Hill Tracts (CHT) of Bangladesh, as an example, and assesses the response of biologists to this conflict. The study spans the last 50 years dividing it into three periods: pre-conflict (1961?1974), conflict (1975–1997) and post-conflict (1998–2011). Interactions with selected researchers and a literature survey showed that sporadic, intermittent biological research was conducted in this region even during the conflict. The number of research initiatives substantially increased and became more diverse over the last decade. Research opportunity has increased mainly because of improved security and accessibility. Nevertheless, despite the research capacity and a positive attitude among the researchers, some fundamental issues still limit long-term research in this area. The continuing volatile situation due to slow implementation of the 1997 Peace Accord and the tension between rebel factions and indigenous and settler communities in some areas continue to be serious concerns for studying and conserving the biodiversity of this region. Innovative research approaches and the full implementation of the peace agreement are vital to improving the situation for biological research in the CHT. The paper underlines the importance of a biologist’s self-motivation to respond to low-intensity armed conflicts.  相似文献   
92.
This paper describes the synthesis and spectral investigations of two amino derivatives of N-methyl-N-(2,4,6-trinitrophenyl)nitramine (tetryl). Also discussed are the results from thermal decomposition studies on the three explosives, viz. tetryl, 3-aminotetryl (3 AT) and 3,5-diaminotetryl (3,5 DAT) and preliminary work on the explosive properties of the last two compounds. The aminotetryls have been prepared by the amination of the corresponding chlorotetryls. The yield was 87% for 3 AT, but was only 33% for 3,5 DAT, probably due to steric crowding around the benzene nucleus. The mass spectra show interesting differences in the electron impact fragmentation patterns of the three tetryls with the M+ ion relative intensities following the order 3,5 DAT > 3 AT > tetryl, which could be due to (a) resonance stabilization and (b) hydrogen bonding effects. Evidence for the latter is also found in the infrared spectra of these compounds. Arrhenius kinetic parameters derived from thermal decomposition studies of the three compounds are presented and show that 3,5 DAT is thermally less stable than 3 AT. Explosive sensitiveness tests indicate that the diamino compound is the most sensitive, the trend being 3,5 DAT > 3 AT > tetryl. This is contrary to the generally found desensitizing influence of NH2 groups on the thermal stability and explosive sensitiveness of trinitroaromatic energetic molecules. Mechanisms to account for the observed thermal decomposition behaviour and explosive sensitiveness patterns are discussed.  相似文献   
93.
It was hypothesized that increasing levels of anxiety about health issues would make response times to disease detections longer than response times to health promotion behaviors and that this effect would reverse when anxiety about health issues was decreased. In a laboratory study 82 participants recruited from undergraduates and the general community were randomly assigned to read information designed either to increase or to decrease anxiety about health. Following the anxiety manipulation participants were required to indicate their attitude about both disease detection and health promotion behaviors and response times to both types of behavior were recorded. Finally, the participants' attitudes toward all the health behaviors were measured using 9-point scales. The results supported the hypothesis.  相似文献   
94.
Hemodynamics and left ventricular myocardial contractility in 170 patients who underwent surgery of prostatic adenoma were examined in preoperative period and 16 days after single-stage transvesical adenomectomy. The age of the patients varied from 52 to 85 years. Echocardiography and the dilution method were used for the evaluation. The increase of end-diastolic and end-systolic volumes, stroke volume, cardiac index, was registered. The combined pharmacological treatment made it possible to decrease the number of operative and postoperative cardiovascular complications.  相似文献   
95.
The calcium-induced calcium release channel of the cardiac sarcoplasmic reticulum has been reported to inactivate in a novel manner (termed "adaptation"), which permits reactivation by exposure to successively higher concentrations of calcium. I examined the limitations placed by thermodynamics on the possible kinetic mechanisms for such behavior. The mechanism suggested by Gyorke and Fill, in which the affinity of a calcium-binding site decreases during adaptation, is not thermodynamically feasible for a passive system, but requires an external input of free energy. Possible sources of such energy are 1) metabolic energy, which is excluded by the fact that adaptation was observed in isolated channels in the absence of ATP, or 2) coupling of ion permeation to gating, for which there is currently no evidence. I derived a general limit on the thermodynamic feasibility of a sequence of channel activations and adaptations, irrespective of channel kinetics, from the requirement that the free energy must decrease during the spontaneous evolution of the system from the state existing immediately after a step increase in [Ca2+] to the state of maximum open probability that follows. The opening of the channel must involve an increase in free energy, which must be compensated by the free energy released by the incremental binding of calcium. This requirement leads to a complicated system of inequalities, which was simplified and manipulated algebraically into the form of a linear programming problem. Numerical solution of this problem showed that the sequence of adaptations of the SR channel observed by Gyorke and Fill requires the presence of at least 10 calcium-binding sites on the channel if it is to occur in the absence of exogenous sources of free energy. This indicates either that a large number of calcium-binding sites participate in the regulation of the SR calcium release channel, or that the existing data are significantly flawed with respect to the low open probability in the resting state, the importance of "calcium spike" artifacts from flash photolysis, or both.  相似文献   
96.
The psychopathology and associated disabilities experienced by persons with schizophrenia have only partially responded to conventional pharmacological and psychosocial treatment approaches. Biobehavioral treatment and rehabilitation employs behavioral assessment, social learning principles, skills training, and a focus on the recovery process to amplify the effects of pharmacotherapy. Utilizing the Medline database, we review a selection of English-language studies published from 1970 to 1994 that support the effectiveness of each of the components of biobehavioral therapy, such as case management, psychopharmacology with behavioral assessment, psychoeducation, family involvement, and social skills training. An integrated biobehavioral therapy directed toward early detection and treatment of schizophrenic symptoms, collaboration between consumers and caregivers in managing treatment, family and social skills training, and teaching coping skills and self-help techniques has been documented to improve the course and outcome of schizophrenia, as measured by symptom recurrence, social functioning, and quality of life. A case vignette is presented to illustrate the successful integration of biobehavioral therapies into a treatment system that focuses on consumers' attempts to become increasingly responsible for recovering from illness.  相似文献   
97.
Although lithium continues to be regarded as the treatment of choice for bipolar disorders, the clinical use of this mood stabiliser is associated with an extremely narrow therapeutic range. Relatively minor increases in serum concentrations may induce serious adverse sequelae, and concentrations within the therapeutic range may result in toxic reactions. The safety of combining lithium with other medications, therefore, is a major concern, and extensive clinical experience has served to identify several significant drug interactions. Lithium removal from the body is achieved almost exclusively via renal means. As a result, any medication that alters glomerular filtration rates or affects electrolyte exchange in the nephron may influence the pharmacokinetic disposition of lithium. Concomitant use of diuretics has long been associated with the development of lithium toxicity, but the risk of significant interactions varies with the site of pharmacological action of the diuretic in the renal tubule. Thiazide diuretics have demonstrated the greatest potential to increase lithium concentrations, with a 25 to 40% increase in concentrations often evident after initiation of therapy. Osmotic diuretics and methyl xanthines appear to have the opposite effect on lithium clearance and have been advocated historically as antidotes for lithium toxicity. Loop diuretics and potassium-sparing agents have minor variable effects. Nonsteroidal anti-inflammatory drugs (NSAIDs) have also been associated with lithium toxicity, although the relative interactive potential of specific NSAIDs is difficult to determine. Small prospective studies have demonstrated large interindividual differences in lithium clearance values associated with different NSAIDs. A growing body of evidence also suggests that ACE inhibitors may impair lithium elimination, but further investigations are needed to identify patients at risk. Anecdotal reports have linked numerous medications with the development of neurotoxicity without an apparent effect on the pharmacokinetic disposition of lithium. Antipsychotics, anticonvulsants and calcium antagonists have all be implicated in a sufficient number of case reports to warrant concern. As these medications have all been commonly coadministered with lithium, the relative risk of serious interactions appears to be quite low, but caution is advised.  相似文献   
98.
99.
This study was designed to evaluate the effect of laser energy at nonablative levels on the ultrastructure of joint capsular collagen. The femoropatellar joint capsules of six mature New Zealand white rabbits were harvested immediately after death. Specimens were divided into three treatment groups (5, 10, and 15 watts) and one control group. Laser energy was applied using a holmium: YAG laser. Transmission electron microscopy showed significant ultrastructural alterations in collagenous architecture for all laser treatment groups, with increased fibril cross-sectional diameter for each of the treated groups. The fibrils began to lose their distinct edges and their periodical cross-striations at subsequently higher energy densities. A morphometric analysis showed that each subsequently higher laser energy caused a significant increase in collagen fibril diameter. Ultrastructural alteration of collagen fibril architecture caused by the thermal effect of laser energy is probably the dominant mechanism of laser-induced tissue shrinkage.  相似文献   
100.
Fifty-one Staphylococcus aureus strains lacking mec for which oxacillin MICs were 1 to 8 micrograms/ml were tested against oxacillin and the combination of oxacillin and clavulanic acid with the Vitek GPS-SA card, the reference broth microdilution method, and the oxacillin agar screen plate. Of the 51 strains, 44 (86%) did not grow on the oxacillin agar screen plate, broth microdilution MICs were 1 to 2 micrograms/ml, and GPS-SA card MICs were < or = 2 micrograms/ml, with the exception of 3 strains that failed to grow in the card on repeated attempts. Another seven strains did grow on the oxacillin agar screen plate. For four of the latter group of strains, oxacillin broth microdilution MICs were > 4 micrograms/ml and GPS-SA card MICs were > or = 4 micrograms/ml; for the other 3 strains, corresponding MICs were 4 and < or = 2 micrograms/ml, respectively. The GPS-SA card classified 86% of strains as oxacillin susceptible.  相似文献   
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