Dynamic shock wave driven simultaneous crystallographic and molecular switching between α-Fe2O3 and Fe3O4 nanoparticles - a new finding.

Switchable nanostructured materials with a low-cost and fast processing have diverse practical applications in the modern electronic industries, but such materials are highly scarce. Hence, there is a great demand for identifying the externally stimulated solid-state switchable phase transition materials for several industrial applications. In this paper, we present the experimentally observed solid-state molecular level switchable phase transitions of nanocrystalline iron oxide materials: {α-Fe2O3 (R-3c) to Fe3O4 (Fd-3m) and Fe3O4 (Fd-3m) to α-Fe2O3 (R-3c)} under dynamic shock wave loaded conditions, and the results were evaluated by diffraction, and vibrational and optical spectroscopic techniques. To date, this is most probably the first report which demonstrates the simultaneous molecular and crystallographic switchable-phase-transitions enforced by dynamic shock waves such that the title material is proposed for sensors and molecular switching applications.

'Health, Environment and Training': Guidance on conduct of physical exertion in hot and humid climates.

BACKGROUND: Military operations and training in hot environments present a special set of challenges to medical personnel who must support them. METHODS: Various meteorological parameters such as relative humidity (RH), ambient air temperature (Ta) and radiant temperature (Tg), were evaluated at training sites in a desert region. Development of a colour coded Heat Stress Prevention Decision Aid Tool was done using an existing guideline chart. RESULTS: Temperatures were being recorded routinely by ordinary meteorological instruments mounted within a Stevenson Screen. Onsite measurements with a USB datalogger was found to be relevant in making a decision on suitability of weather for conduct of training. Heat casualties occur when the stresses imposed by some combination of environment, work, and clothing combine to exceed individual tolerance limits. Personnel may encounter high environmental heat loads while working outdoors; during road marches; and while carrying loads or undertaking mechanical maintenance activities. Preventive strategies cannot be expected to eliminate heat stress but should minimize its impact on training while preserving the health of personnel to the extent possible. CONCLUSION: It is recommended that onsite measurement of meteorological parameters should be done, and a decision tool should be utilized for arriving at a spot decision by junior leaders.

Dengue in the deserts: Search and Destroy Operations.

Dengue, a viral disease transmitted by the Aedes mosquito has the potential to cause outbreaks in urban settings. Planned and coordinated actions including entomological surveillance need to be undertaken at the community level, through synergized efforts by all partners and stakeholders. The experience of conducting such a Task Force based action plan for prevention and control of dengue, in a desert township is highlighted in this study.

Thermal decomposition of propargyl alcohol: single pulse shock tube experimental and ab initio theoretical study.

Thermal decomposition of propargyl alcohol (C3H3OH), a molecule of interest in interstellar chemistry and combustion, was investigated using a single pulse shock tube in the temperature ranging from 953 to 1262 K. The products identified include acetylene, propyne, vinylacetylene, propynal, propenal, and benzene. The experimentally observed overall rate constant for thermal decomposition of propargyl alcohol was found to be k = 10((10.17 ± 0.36)) exp(-(39.70 ± 1.83)/RT) s(-1). Ab initio theoretical calculations were carried out to understand the potential energy surfaces involved in the primary and secondary steps of propargyl alcohol thermal decomposition. Transition state theory was used to predict the rate constants, which were then used and refined in a kinetic simulation of the product profile. The first step in the decomposition is C-O bond dissociation, leading to the formation of two important radicals in combustion, OH and propargyl. This has been used to study the reverse OH + propargyl radical reaction, about which there appears to be no prior work. Depending on the site of attack, this reaction leads to propargyl alcohol or propenal, one of the major products at temperatures below 1200 K. A detailed mechanism has been derived to explain all the observed products.

Prolonged constriction of sciatic nerve affecting oxidative stressors & antioxidant enzymes in rat.

BACKGROUND & OBJECTIVE: This study was carried out to determine the effects of reactive oxygen species in the balance between the pro-oxidant and antioxidant levels in experimental peripheral constriction injury induced by silver wire looping of sciatic nerve of rats. METHODS: Rats were divided into experimental group 1 (silver wire ligated) and group 2 (control, sham operated). Functional and behavioural activities were assessed by a modified Basso Beattie Bresnahan (BBB) locomotory rating scale. Mechanical pain intensity was measured with Randall and Selitto apparatus. Foot positioning, toe spread, paw withdrawal threshold and paw withdrawal latency were carried out on days 1, 3, 7, 14, 21 and 28 in rats with chronic pain. Oxidative stress markers such as malondialdehyde (MDA) and advanced oxidation protein products (AOPP) were measured along with antioxidants such as glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) on day 30 after constriction in sciatic nerve, spinal cord, dorsal root ganglion, dorsal root and ventral root. RESULTS: Significant (P<0.05) increase in MDA, AOPP, SOD and GPx and decrease in the GSH and catalase activities in sciatic nerve, spinal cord, dorsal root ganglion, dorsal root and ventral root were observed in experimental group rats compared to control group. There was no recovery in foot positioning and toe spread. Reduced paw withdrawal threshold and paw withdrawal latency was observed in ligated rats compared to control rats. INTERPRETATION & CONCLUSION: Foot positioning, toe spread, paw withdrawal threshold and paw withdrawal latency with no recovery until day 30 confirmed locomotory deficits, hyperalgesia and neuronal impairment. Oxidative stress evidenced by increased MDA, AOPP and decreased GSH and catalase support the generation of reactive oxygen species in constriction model. The present experimental model for chronic pain induced by silver wire spirally coiled around sciatic nerve may be useful for future studies.

ac susceptibility and ESR studies on vapour phase grown Cd(1-x)Mn(x)Te crystals.

Single crystals of Cd(1-x)Mn(x)Te for x = 0.1, 0.2, 0.3, 0.4 and 0.5 were grown by a modified vapour phase growth technique. ac magnetic susceptibility studies were carried out in the temperature range 14-300 K. Both the real and the imaginary parts of susceptibility indicated the formation of spin-glass phase at low temperatures. ESR spectra were recorded at room temperature (300 K) at 9.4 GHz for samples of all compositions. The line width (DeltaH) increased with Mn content.

Failure of conservative management after the passage of a distal colonic "cast": report of a case.

PURPOSE: The spontaneous passage per rectum of a full-thickness colon "cast" is a rare consequence of acute colonic ischemia. Previous cases have undergone surgery soon afterward because of intractable symptoms. We report a patient who was managed conservatively for 11 months but ultimately required definitive surgery. METHODS: The clinical, radiographic, pathologic, and endoscopic findings were obtained from the case notes and compared with previously reported cases. RESULTS: A 67-year-old obese patient underwent a Hartmann's procedure for a perforated diverticular abscess, which was reversed six months later. On the first postoperative night after the reversal, she had a brief hypotensive episode, and three weeks later passed a 21-cm, full-thickness infarcted piece of colon. She did not develop peritonitis and for 11 months experienced only mild symptoms. Under colonoscopic surveillance, the granulation tissue conduit connecting the remaining viable bowel became increasingly stenosed proximally and difficult to dilate. After three rapidly consecutive episodes of large-bowel obstruction, she required a laparotomy to resect the stricture and restore bowel continuity. From a literature review, this is the eighth case of its kind and the first in which such prolonged conservative management has been possible. CONCLUSIONS: When symptoms permit, it is feasible to manage patients conservatively in the short-term after this unusual event to allow recovery from the initial insult and planning of future surgery. However, definitive treatment is surgical and colonoscopic management should not delay this once the patient is fit for surgery.

Melatonin in medically ill patients with insomnia: a double-blind, placebo-controlled study.

BACKGROUND: It has been suggested that melatonin improves sleep functioning, but this possibility has not been studied in medical populations. METHOD: 33 medically ill persons with initial insomnia were randomly assigned to receive either melatonin (N = 18) or placebo (N = 15) in a flexible-dose regimen. Double-blind assessments of aspects of sleep functioning were obtained daily across the next 8 to 16 days. RESULTS: The mean stable dose of melatonin was found to be 5.4 mg. Relative to placebo, melatonin significantly hastened sleep onset, improved quality and depth of sleep, and increased sleep duration without producing drowsiness, early-morning "hangover" symptoms, or daytime adverse effects (p < .05). Melatonin also contributed to freshness in the morning and during the day and improved overall daytime functioning. Benefits were most apparent during the first week of treatment. CONCLUSION: Melatonin may be a useful hypnotic for medically ill patients with initial insomnia, particularly those for whom conventional hypnotic drug therapy may be problematic.

Effects of zopicloone and Lorazepam on ect seizure duration : clinical implications of findings from an animal model.

Lorazepam is commonly prescribed to treat insomnia in depressed patients who receive electroconvulsive therapy (ECT); however, lorazepam may interfere with ECT seizure parameters, and may thereby compromise the efficacy of the treatment. This study therefore sought to assess whether zopicione, a hypnotic agent, interferes less with the ECT seizure. For ethical reasons, the study utilized an animal model. Sprague-Dawley rats (n=10/group) received either zopicione (1.5 mg/ kg), lorazepam (0.2 mg/kg), or a placebo equivalent. After 30 minutes, an electroconvulsive shock was administered to the rats. It was observed that the motor seizure duration but not the total motoric phase was significantly attenuated by zopicione. Lorazepam did not impact significantly upon either seizure measure. It is concluded that zopicione may be a suitable hypnotic for patients receiving ECT only if sufficient time is allowed for the drug to be substantially washed out of the body.

Reduced nociceptive responses in mice with alloxan induced hyperglycemia after garlic (Allium sativum Linn.) treatment.

Administration of ethanol (95%) extract (45 mg/kg body wt/day for 28 days) of garlic (A. sativum) to alloxan induced diabetic (ALX-D) mice significantly lowered the serum glucose levels, nociceptive response in tail-flick, hotplate, allodynia, formalin test and relative thickness, weight of hind paw in formalin induced Paw oedema test, over 28 days, thus, showing the reversal trend in hyperglycemia and hyperalgesia compared to ALX-D mice. The reversal of hyperglycemia and hyperalgesia was progressive and more effective as duration of extract administration increased. The results suggest therapeutic potential of ethanol extract of garlic for anti-hyperglycemic and anti-nociceptive effects in diabetes.

Transient elevations of AChE in soleus, plantaris and EDL muscles of palm squirrel (Funambulus palmaram) during prolonged reinnervation.

Recovery of acetylcholinesterase (AChE) activity after nerve crush was observed at second week in soleus (slow-extensor) and plantaris (fast-extensor) muscles whereas the same was observed in extensor digitorum longus (fast-flexor) only after third week. In contrast to earlier observations the AChE was found to exhibit specific transient elevations with intermittent reversal to control values in different type of skeletal muscles during later periods of reinnervation.

Redifferentiation and subsequent dedifferentiation of the livers of roosters resulting from acute estrogen challenges.

1. Histologic and metabolic changes take place in livers of rooster receiving challenges consisting of acute doses of estrone. 2. During initial Growth and Redifferentiation livers rapidly increase in size by division of hepatocytes within most lobules, changing from cordlike to acinar configurations. 3. No new lobules appear and degeneration of some cells within lobules takes place even as cell divisions predominate. 4. Cells within lobules assume secretory features. 5. Vitellogenins, very low density lipoproteins, calcium and alkaline phosphatase increase greatly in plasma. 6. Within 35-40 days of cessation of estrogen, livers have returned to near normal sizes and plasmas exhibit normal parameters.

Immunologic and morphologic effects of cryosurgery of the monkey (macaque) prostate.

A reduction in size of the Macaque prostate following single and multiple in situ freezings was accompanied by histologic alterations, which occurred predominately in the caudal lobe and were characterized by what appeared to be specific periacinar foci of lymphocytic infiltrates. These lymphocytes were observed to infiltrate onto acinar epithelial cells, resulting in their subsequent separation from the basal lamina and epithelial destruction. Other histologic alterations were in consonance with studies of the prostate following cryosurgery by others. Circulating antibodies specific for prostate were present in only one of the seven animals at the time at which these histologic observations were made. These observations suggest the possible development of a cellular immunologic response following cryosurgery of the prostate. The relevancy of these observations to those obtained following cryoprostatectomy in man and other species is considered. Pending confirmation, they may be of potential significance in providing an explanation of reported cases of eradication of human prostatic carcinomas following cryotherapy.

Cholangiocarcinomas induced by feeding 3'-methyl-4-dimethylaminoazobenzene to rats. Histopathology and ultrastructure.

Thirty-three male Sprague-Dawley rats were fed a carcinogenic (0.064% 3'-methyl-4-dimethylaminoazobenzene, 3'-Me-DAB) ground meal normal diet. After 12 weeks the ground meal diet was replaced with a normal pellet diet, and the 30 surviving animals were divided into three equal groups. One group was sacrificed at the twelfth week and the other groups 4 and 8 weeks later. Control animals were also run. Based on previous studies which used "tumor-promoting" diets and 3'-Me-DAB, we expected a less than 100% incidence of predominantly hepatocellular carcinomas. However, we found mucin-producing cholangiocarcinomas in all 30 animals and, in addition, a small hepatocellular component in 3 of the animals. By electron microscopy the intestinal mucosal features of microvillous border cells, goblet cells, and endocrine-like cells were found. We suggest that the tumors produced as described here provide a good animal model of mucin-producing cholangiocarcinomas.

B-complex vitamins in cultured and acidified yogurt.

Studies were to determine the effect of various factors upon B-vitamin content of cultured yogurt and to compare the B-vitamin contents of cultured and direct acidified yogurt. Incubation of yogurt culture at 42 C for 3 h yielded maximum vitamin synthesis concurrent with optimal flavor and texture qualities. A method was standardized for the manufacture of direct acidified yogurt involving the use of Stabilac acidulant and nonfat dry milk, Carboxymethyl cellulose, gelatin, and Starite. Acidified yogurt showed a slightly higher content of certain B-vitamins than the cultured yogurt due to the contribution made by various food additives. Both cultured and acidified yogurt showed good keeping quality and freedom from microbial contaminants during storage at 5 C for 16 days. However, folic acid and vitamin B12 contents decreased 29 and 60% in cultured yogurt and 48 and 54% in acidified yogurt.