Interaction mechanism between TiO2 nanostructures and bovine leukemia virus proteins in photoluminescence-based immunosensors

In this research a mechanism of interaction between a semiconducting TiO₂ layer and bovine leukemia virus protein gp51, applied in the design of photoluminescence-based immunosensors, is proposed and discussed. Protein gp51 was adsorbed on the surface of a nanostructured TiO₂ thin film, formed on glass substrates (TiO₂/glass). A photoluminescence (PL) peak shift from 517 nm to 499 nm was observed after modification of the TiO₂/glass by adsorbed gp51 (gp51/TiO₂/glass). After incubation of the gp51/TiO₂/glass in a solution containing anti-gp51, a new structure (anti-gp51/gp51/TiO₂/glass) was formed and the PL peak shifted backwards from 499 nm to 516 nm. The above-mentioned PL shifts are attributed to the variations in the self-trapped exciton energy level, which were induced by the changes of electrostatic interaction between the adsorbed gp51 and the negatively charged TiO₂ surface. The strength of the electric field affecting the photoluminescence centers, was determined from variations between the PL-spectra of TiO₂/glass, gp51/TiO₂/glass and anti-gp51/gp51/TiO₂/glass. The principle of how these electric field variations are induced has been predicted. The highlighted origin of the changes in the photoluminescence spectra of TiO₂ after its protein modification reveals an understanding of the interaction mechanism between TiO₂ and proteins that is the key issue responsible for biosensor performance.

In this research a mechanism of interaction between a semiconducting TiO₂ layer and bovine leukemia virus protein gp51, applied in the design of photoluminescence-based immunosensors, is proposed and discussed.     

Cysteine-Induced Hybridization of 2D Molybdenum Disulfide Films for Efficient and Stable Hydrogen Evolution Reaction

The noble, metal-free materials capable of efficiently catalyzing water splitting reactions currently hold a great deal of promise. In this study, we reported the structure and electrochemical performance of new MoS₂-based material synthesized with L-cysteine. For this, a facile one-pot hydrothermal process was developed and an array of densely packed nanoplatelet-shaped hybrid species directly on a conductive substrate were obtained. The crucial role of L-cysteine was determined by numerous methods on the structure and composition of the synthesized material and its activity and stability for hydrogen evolution reaction (HER) from the acidic water. A low Tafel slope of 32.6 mV dec⁻¹, close to a Pt cathode, was registered for the first time. The unique HER performance at the surface of this hybrid material in comparison with recently reported MoS₂-based electrocatalysts was attributed to the formation of more defective 1T, 2H-MoS₂/MoO_x, C nanostructures with the dominant 1T-MoS₂ phase and thermally degraded cysteine residues entrapped. Numerous stacks of metallic (1T-MoS₂ and MoO₂) and semiconducting (2H-MoS₂ and MoO₃) fragments relayed the formation of highly active layered nanosheets possessing a low hydrogen adsorption free energy and much greater durability, whereas intercalated cysteine fragments had a low Tafel slope of the HER reaction. X-ray photoelectron spectroscopy, scanning electron microscopy, thermography with mass spectrometry, high-resolution transmission electron microscopy, Raman spectroscopy techniques, and linear sweep voltammetry were applied to verify our findings.     

Immobilization of Hexavalent Chromium Using Self-Compacting Soil Technology

A study of immobilization of hexavalent chromium in the form of Na₂CrO₄ salt by self-compacting soils (SCS) is presented. Carbofill E additive was used as SCS binder. The efficiency of immobilization of Cr (VI) was evaluated by washing out chromium compounds from SCS samples. The influence of the nature of the soil and the content of Carbofill E and Na₂CrO₄ in the SCS samples on the efficiency of Cr (VI) immobilization was studied. It was found that the nature of the soil and the content of Carbofill E in the SCS samples affect the immobilization of Cr (VI). Moreover, increasing the Carbofill E content in SCS samples further increases Cr (VI) immobilization. X-ray diffraction studies of the samples with immobilized hexavalent chromium showed that part of the sample transforms from a readily soluble form of salt into oxide forms of chromium and calcium-chromium, which are practically insoluble in water.     

A surgical experience with Crohn's disease

From 427 histories of patients with Crohn's disease admitted to St. Michael's Hospital between 1 January 1974 and 31 March 1983, 152 patients were studied as each had at least one operation related to the disease. The age at onset of symptoms, the interval between onset of symptoms and operation, the site of disease, operations performed, the type and frequency of repeat operations and the morbidity, mortality and follow-up period were studied. The small intestine only was involved in 55 per cent of the patients, the large intestine only in 16 per cent, and both the small and large intestine in 29 per cent. The most frequent indication for operation was obstruction (29 per cent); the next was perianal disease (18 per cent). The most common procedure was resection of the lowest segment of the small intestine with adjacent colon (37 per cent). The second most common operation was perianal operation (19 per cent). There were three deaths (2 per cent mortality rate). One hundred and thirty patients (93 per cent) have been examined within the past three years. Life tables show the cumulative chance of having an operation for Crohn's disease.     

A double-blind comparative study of doxazosin and nitrendipine in patients with mild-to-moderate essential hypertension

The antihypertensive efficacy and safety of doxazosin, a selective α₁-inhibitor, were compared with nitrendipine. Seventy-two hypertensive patients were entered into the 18-week, double-blind parallel group study, which involved three phases: a 4-week baseline period, a 10-week period in which patients received 1 to 8 mg of doxazosin or 10 and 20 mg of nitrendipine once daily, and a 4-week maintenance period. For all patients, the mean final daily doses were 2.5 mg for doxazosin and 13.9 mg for nitrendipine. In efficacy evaluable patients the percentages of therapy successes (standing diastolic blood pressure ≤90 mm Hg with ≥5 mm Hg reduction or ≥10 mm Hg decrease) were comparable for doxazosin (94%) and nitrendipine (91%), as was the proportion in whom blood pressure was “normalized” (standing diastolic blood pressure ≤90 mm Hg). 91% and 85, respectively. Blood pressures (diastolic and systolic in supine and standing positions) were significantly reduced (p < 0.05) at all visits in both treatment groups. Ten patients (28%) in each treatment group experienced at least one adverse event. No clinically significant laboratory changes were apparent in either the doxazosin or nitrendipine groups, and no trends were observed with regard to organ systems or correlations with dose or duration of treatments. The investigators' global assessment of efficacy was rated excellent or good for all doxazosin-treated patients and excellent or good for 32 and fair for four in the nitrendipine group. The investigators' global assessment of patient toleration of doxazosin was excellent or good for 34 patients and poor for two. Toleration of nitrendipine was excellent or good in 33 patients and fair in three. Lipid parameters did not differ significantly between groups. From baselline to final visit there were highly significant reductions (p < 0.001) in the calculated coronary heart disease risk scores on the basis of the Framingham equation, for both treatment groups.     

Atypical complications of gastric bypass surgery

Although gastric bypass surgery continues to grow in popularity for weight loss and weight maintenance in the morbidly obese, there has been little attention given to the imaging of complications associated with these surgeries. The purpose of our study is to demonstrate the variety of gastric bypass surgery complications that can be identified radiographically, with attention to the more unusual complications. This study was performed with institutional Internal Review Board approval. We performed a 5-year retrospective review of all patients who had undergone gastric bypass surgery, had complications of the surgery, and had studies performed in our department to image these complications. These studies consisted of contrast fluoroscopy and CT. We identified the more common complications of anastomotic stenoses and anastomotic leaks. We also identified six unusual complications as follow: (1) internal herniation through the small bowel mesentery, (2) internal herniation through the transverse mesocolon, (3) external herniation through the abdominal wall incision, (4) enterocutaneous fistulas, (5) antiperistaltic construction of the Roux-en-Y, and (6) incorrect anstomoses of the Roux limbs resulting in a Roux-en-O configuration. Our findings show that a thorough understanding of expected postoperative bowel configuration is essential in the evaluation of these patients. In addition, fluoroscopic evaluation should assess not only anatomy, but also motility.     

Perceptions of assertive community treatment in the UK and Lithuania

BACKGROUND: There is current uncertainty over the future of assertive community and outreach teams in view of recent evidence suggesting that they no longer reduce hospital admissions. Despite this, assertive teams remain popular among practitioners. AIMS: To examine the views of assertive community team members and other mental health professionals in London (UK) and Vilnius (Lithuania) to determine important differences in attitudes. METHOD: A questionnaire, involving the assessment of statements giving common opinions on assertive community teams, was given to 62 staff in Vilnius, Lithuania and West London, UK, 33 from assertive community or outreach teams and 29 from other mental health professionals. RESULTS: The results of the questionnaire showed that personnel in experienced assertive outreach teams in London believed that they gave more intensive care (p < 0.001), felt it of greater value to see patients in the community (p < 0.001) and were not just well-resourced community teams with low caseloads (p < 0.01) than did other groups, but they placed lower value on assertiveness (p = 0.04) and comprehensive care (p < 0.04). These differences were less marked in Lithuania where staff regarded home treatment as similar to clinic treatment and were more supportive of comprehensive care. CONCLUSION: The results suggest that in experienced community teams the notion of assertiveness has become less important in planned intensive community care and so the term ACT may be outmoded. However, for countries such as Lithuania, somewhat similar to the United States in 1972 when ACT began, the original principles are still appropriate and 'assertive' is a major component of their effectiveness.     

Indium 111-labeled granulocyte scan in the diagnosis and management of acute inflammatory bowel disease

The indium 111 granulocyte scan was used to evaluate 39 individuals known to have or suspected of having inflammatory bowel disease. Twenty-three of these individuals had positive scans and 16 had negative scans. Eighty-seven confirmatory studies, which consisted of barium radiography, endoscopy, operative findings, and histopathology, were performed in 37 of these individuals. The remaining two negative scans corroborated only by clinical course, CBC, and erythrocyte sedimentation rate. In addition, 10 follow-up scans were performed in six of the 39 patients to monitor therapy or investigate a change in symptoms. As an anatomic indicator of acute granulocytic infiltration of the intestinal lamina propria and crypts, the authors found that this scan had a 97 percent rate of sensitivity and 100 percent specificity. Specific indications for the use of the indium 111-labeled granulocyte scan are described. For the authors, in general, this test has become a vital adjunct to endoscopy and radiography in the diagnosis and management of patients with symptoms of inflammatory bowel disease.Read at the meeting of The American Society of Colon and Rectal Surgeons, Toronto, Canada, June 11 to 16, 1989. This paper received the New York Society of Colon and Rectal Surgeons A. W. Martin Marino, Sr., M.D., Award.