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1.
Using dissociated spiral ganglion cell cultures obtained from 3-day-old rat cochlea, we investigated the response of auditory neurones to gamma-aminobutyric acid (GABA) using patch-clamp techniques. In our recording conditions, GABA elicited inward currents in > 95% of the neurones which reversed around 0 mV. Similar inward currents were measured using isoguvacin, a specific agonist of GABAA receptors. GABA-gated currents were reversibly inhibited by the channel blocker picrotoxin and the GABA competitive antagonist bicuculline. These functional GABAA receptors are characterized by an insensitivity to benzodiazepines and a relatively high sensitivity to beta-carbolines and barbiturates. These results show that the GABAA receptor pharmacological properties of spiral ganglion neurones are close to those of cerebellar granule cells.  相似文献   
2.
Recently, magnetic separation of adsorbent materials has attracted much attention for abatement of water pollutants. Due to the strong magnetic property and environmental beneficial behavior Fe3O4 NPs were used to modify local bentonite clay. The prepared magnetite intercalated Bentonite clay composite (Fe3O4-AC) structure and magnetic property were confirmed by powder X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The prepared Fe3O4-AC composite has shown a superior adsorption efficiency to Congo red (CR) dye over acid activated bentonite clay (AC). The enhanced adsorption of the Fe3O4 NPs intercalated in the layer of bentonite could be ascribed to the enhanced surface area and the prevention of the activated clay agglomeration. The optimum removal efficiency was analyzed using Response Surface Methodology (RSM) based Box-Benhken Design (BBD). The optimum conditions for maximum adsorption % removal were found to 94.9% at 105 min, 0.6 g Fe3O4-AC composite, 10 mg. L−1, and pH =4. The adsorption isotherms and Kinetics process were indicated that the experimental data are well fitted to Langmuir and pseudo-second-order models.  相似文献   
3.

Background  

Food insecurity not only affects physical growth and health of children but also their intellectual development, school attendance and academic performance. However, most evidences are based on studies in high income countries. Although food insecurity is common in Ethiopia, to what extent it affects school attendance and educational attainment of adolescents is not explored. We hypothesized that food insecure adolescents would be more likely to be absent from school and have lower grades attained after 1 year compared to their food secure peers.  相似文献   
4.
Liquid and vapour n-hexane sorption/desorption were studied on homogeneous poly(ethylene-co-octene)s produced by metallocene-catalyzed polymerisation covering a crystallinity range from 3.5 to 72.4%. Crystal core contents determined by Raman spectroscopy were lower than those determined by density assessments, particularly at low degrees of crystallinity. The solubility showed deviation from Henry's law. The solubilities of n-hexane in the homogeneous copolymers depended in a non-linear manner on the content of penetrable polymer component and were lower than those earlier reported for heterogeneous copolymers at the same contents of penetrable component. The concentration dependence of the thermodynamic diffusivity predicted by the Cohen-Turnbull-Fujita free volume theory was confirmed by the data obtained by the differential method and the differences between the results obtained from the integral and differential methods were within the margins of experimental error. The fractional free volume of the penetrable polymer fraction increased with increasing fraction of penetrable polymer and with relative proportion of liquid-like component in the penetrable polymer fraction. The homogeneous copolymers showed a decreasing trend in the geometrical impedance factor with increasing degree of crystallinity.  相似文献   
5.
Oreochromis niloticus is the dominant commercial fish in the Lake Tana region. However, its fishery is progressively declining over time. Little or no updated information exists on the population dynamics and exploitation patterns of the species, which is crucial to guide its sustainable management. Accordingly, the purpose of the present study was to generate essential biological parameters on the growth, mortality and stock status of O. niloticus, using length‐frequency data collected monthly from the commercial fish catches of 1 year (2014–2015). The total mortality coefficient (Z) was derived from the length‐converted catch curve. Biological reference points were predicted from relative yield‐ and biomass‐per‐recruit analyses. The estimated values of the von Bertalanffy growth parameters were L = 44.1 cm, K = 0.44/year, and t0 = ?0.34/year, and the growth performance index (Φ′) was 2.93. The total mortality (Z), natural (M) and fishing mortality (F) rates were 2.37, 0.98 and 1.39 per year, respectively. The current fishery exploitation rate of 0.59 exceeds the estimated biological reference points of Emax (0.52), confirming the stock of O. niloticus in the lake is being overexploited above optimum levels. Size indicators of the catches further illustrate 31% of the landed fish are harvested before reaching sexual maturity, with mega‐spawners comprising only 15%. This indicates the stock is suffering from both growth and recruitment overfishing. The logistic selection model indicated 50% of the fish vulnerable to capture was at 18.14 cm TL. The fish exhibited a year‐round recruitment pattern, with a major peak during May and June. Sustainably managing the fishery, therefore, requires increasing the fish size at first capture (Lc) towards Lopt.  相似文献   
6.
ABSTRACT: BACKGROUND: In resource limited settings, many People Living with HIV/AIDS (PLWHA) lack access to sufficient quantities of nutritious foods, which poses additional challenges to the success of antiretroviral therapy (ART). Maintaining adequate food consumption and nutrient intake levels and meeting the special nutritional needs to cope up with the disease and the ART are critical for PLWHA to achieve the full benefit of such a treatment. OBJECTIVE: To determine the prevalence and correlates of food insecurity among HIV-infected individuals receiving highly active antiretroviral therapy in resource-limited settings. METHODS: A cross sectional study was carried out from January 1, 2009 to March 3, 2009 at ART clinic at Jimma University specialized hospital (JUSH) in Ethiopia. We used multivariable logistic regression model to compare independent risk factors by food insecurity status among 319 adult PLWHA ([greater than or equal to]18 years) attending ART Clinic. RESULTS: A total of 319 adult PLWHA participated in the study giving a response rate of 100%. Out of 319 PLWHA the largest numbers of participants, 46.4% were in the age group of 25-34 years. The overall 201(63.0%) PLWHA were food insecure. Educational status of elementary or lower [OR=3.10 (95%CI; (1.68-5.71)], average family monthly income <100 USD [OR=13.1 (95% CI; (4.29-40.0)] and lower food diversity [OR=2.18 (95%CI; (1.21--3.99)] were significantly and independently associated with food insecurity. CONCLUSION: Food insecurity is a significant problem among PLWHA on HAART. Lower educational status and low family income were the predictors of food insecurity. Food security interventions should be an integral component of HIV/AIDS care and support programs. Special attention need to be given to patients who have lower educational status and are members of households with low income. KEYWORDS: Food insecurity, HAART, PLWHA, HIV/AIDS, Ethiopia.  相似文献   
7.
We introduced open adjustable silicone gastric banding (ASGB) for treatment of morbid obesity in our institution in 1991. It was done in a prospective study comparing ASGB with vertical banded gastroplasty (VBG) with regard to weight loss. After 200 cases of open ASGB and 210 VBG procedures and the encouraging weight loss results, we started laparoscopic placement of the adjustable silicone band. The initial work was done in an animal laboratory program where a new surgical protocol has been established. Details of the laparoscopic dissection around the stomach in a deep operative field and fatty atmosphere have been developed, and a laparoscopically implantable version of the adjustable silicone band (LAGB) has been devised. The first human laparoscopic ASGB procedure was performed in our institution on September 1, 1993. Altogether 350 patients had undergone adjustable silicone gastric banding (LASGB) procedures by May 1997 (277 women, 73 men). All the patients were morbidly obese, with an average preoperative weight of 118 kg (92-200 kg). The mean BMI was 43 kg/m2 (36-65 kg/m2). The conversion rate to laparotomy has been low (1.4%). Early complications have been rare, and pouch dilatation and stomach slippage have been the only significant late complications. The rate of these complications has been considerably improved by reducing the pouch volume and using more gastrogastric sutures. Evaluation of postoperative weight loss of LASGB patients compared with our VBG and ASGB (open) patients showed a similar curve.  相似文献   
8.
Nonnegative matrix factorization (NMF) is an unsupervised learning method for decomposing high-dimensional nonnegative data matrices and extracting basic and intrinsic features. Since image data are described and stored as nonnegative matrices, the mining and analysis process usually involves the use of various NMF strategies. NMF methods have well-known applications in face recognition, image reconstruction, handwritten digit recognition, image denoising and feature extraction. Recently, several projective NMF (P-NMF) methods based on positively constrained projections have been proposed and were found to perform better than the standard NMF approach in some aspects. However, some drawbacks still affect the existing NMF and P-NMF algorithms; these include dense factors, slow convergence, learning poor local features, and low reconstruction accuracy. The aim of this paper is to design algorithms that address the aforementioned issues. In particular, we propose two embedded P-NMF algorithms: the first method combines the alternating least squares (ALS) algorithm with the P-NMF update rules of the Frobenius norm and the second one embeds ALS with the P-NMF update rule of the Kullback–Leibler divergence. To assess the performances of the proposed methods, we conducted various experiments on four well-known data sets of faces. The experimental results reveal that the proposed algorithms outperform other related methods by providing very sparse factors and extracting better localized features. In addition, the empirical studies show that the new methods provide highly orthogonal factors that possess small entropy values.  相似文献   
9.
The influence of mixing method—solution and melt mixing—on the homogeneity and crystallization kinetics of a series of blends of single‐site materials of linear polyethylene and ethyl‐branched polyethylene was studied by differential scanning calorimetry. Data obtained for heats of melting and crystallization, melting and crystallization peak temperatures, and melting and crystallization temperature profiles were essentially the same for the samples obtained by the two mixing methods. The results obtained can be interpreted as indicating that melt mixing is capable of producing homogeneous melts of these relatively low molar mass polymers, given that solution mixing is considered to give perfectly homogeneous blends. The heat associated with the high temperature melting peak after crystallization at 125°C of the blend samples, obtained by the two preparation methods, was higher than that of the linear polyethylene included in the blends, suggesting that a part of the branched polyethylene crystallized at 125°C. The unblended branched polyethylene showed no crystallization at 125°C. Samples obtained by powder mixing showed independent crystallization and melting of the linear and branched polyethylene components. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1730–1736, 2004  相似文献   
10.
The emphasis of the present study is to investigate the potential of magnetic iron oxide nanoparticles synthesized using bagasse from sugarcane (M‐NIOB). M‐NIOB was infused onto the modified batch reactor (M‐BR) stirrers using mesh structures for the adsorption of Cr6+ contained in effluent from the leather industry. M‐NIOB exhibited supermagnetic properties under an external magnetic field with a saturation magnetization value of 9.192 emu/g at room temperature. M‐NIOB nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, vibrating sample magnetometer, and Brunauer–Emmett–Teller analysis. The size of the M‐NIOB particles ranged from 50 to 200 nm. The most favorable time, pH, and temperature for the application of M‐NIOB to Cr6+ removal from tannery effluent was found to be 180 min, 5, and 318 K, respectively. M‐NIOB adsorbent performed its best at an adsorbent dosage of 800 mg/150 mL with a particle size of 150 nm. Kinetic and thermodynamic studies have been conducted. The applicability of various adsorption models for the Cr6+ adsorption data was tested. Moreover, the desorption studies carried out at 60 °C proved the capability of M‐NIOB for regeneration and reuse. Hence, M‐NIOB could be potentially applied for the treatment of effluent that has Cr6+ as a major constituent. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46683.  相似文献   
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