[Identification of factors affecting Oncomelania hupensis density in Eastern Dongting Lake regions].

OBJECTIVE: To evaluate the impact of water pollutants, water levels and meteorological factors on the Oncomelania hupensis density in Eastern Dongting Lake regions, so as to provide insights into schistosomiasis control. METHODS: O. hupensis snails were surveyed using a systematic sampling method in snail-infested marshlands in Eastern Dongting Lake regions from 2007 to 2014, and data pertaining to water pollutants, water levels and meteorological factors were collected. The duration of submergence and the date of the start of submergence were calculated. The snail density and its influencing factors were descriptively analyzed, and a linear mixed model was generated to examine the impacts of variables on the snail density. In addition, smooth curves were fitted to investigate the relationship between snail density and variables. RESULTS: The snail density appeared a fluctuation in Eastern Dongting Lake regions during the period from 2007 to 2014, with the highest density on October, 2010 (52.79 snails/0.1 m2) and the lowest density on January 2009 (2.15 snails/0.1 m2). Linear mixed-model analysis showed that permanganate index, total phosphorus and the date of the start of submergence affected the snail density (t = 6.386, -2.920 and -3.892, all P values < 0.01). Smooth curve analysis revealed that the associations of the snail density with the permanganate index and total phosphorus appeared an approximately quadratic curve. After the end of April, the earlier date of the start of submergence resulted in a higher snail density. CONCLUSIONS: Permenganate index, total phosphorus and the date of the start of submergence affect the O. hupensis snail density in Eastern Dongting Lake regions.

Long-term outcome of telbivudine versus entecavir in treating higher viral load chronic hepatitis B patients without cirrhosis.

Chronic hepatitis B (CHB) patients with higher hepatitis B virus (HBV) load (higher viral load [HVL], HBV DNA ≥1 × 107 copies/mL) require antiviral therapy, but data for evaluating the long-term outcome of this therapy with antiviral agents remain limited. We comparatively evaluated the efficacy and the safety of nucleoside analogues in 179 noncirrhotic CHB patients with HVL over 5 years. The HBeAg-positive (n = 104) or HBeAg-negative (n = 75) patients were treated consecutively with telbivudine (LdT, n = 88) or entecavir (ETV, n = 91) and evaluated for viral response, drug resistance and safety. HBV DNA, viral serology, biochemistries, HBV mutation and off-therapy relapse were determined. The cumulative rates of HBV DNA negativity were 86.4% and 94.5% for LdT and ETV at year 5, respectively. The rates of early viral response (EVR, HBV DNA <103 copies/mL at month 6) under LdT and ETV treatments were 58.0% and 34.1%, respectively (P < .05). Hepatitis B e antigen (HBeAg) and Hepatitis B surface antigen (HBsAg) loss-seroconversions were 47.7% and 18.2% on LdT and 16.5% and 2.2% on ETV (P < .01). Eighteen patients (age 28.2 ± 3.1) experienced HBsAg loss-seroconversion, followed by 33 ± 4.6 month off-therapy without a relapse. Viral mutations and serum creatine kinase elevation were 9.1% and 8.0% on LdT, but only 1.1% and 0% on ETV. Both LdT and ETV suppressed HBV replication in HVL CHB patients within 5 years. LdT therapy achieved a higher EVR, HBeAg and HBsAg seroconversion, especially in the younger patients, whereas ETV caused lower drug resistance and fewer adverse events. This finding might help to identify the optimal treatment for CHB patients with HVL.

Ten-year follow-up of hepatitis B relapse after cessation of lamivudine or telbivudine treatment in chronic hepatitis B patients.

The high rate of relapse after cessation of nucleos(t)ide analogues (NUCs) treatment in chronic hepatitis B (CHB) patients leads us to reassess the feasibility for off-therapy, but long-term follow-up data are scarce. We assessed the feasibility for off-therapy by a long-term observation of relapse in response to lamivudine (LAM) and telbivudine (LdT). Eighty-six NUC-naive CHB patients, treated with LAM (n = 46) or LdT (n = 40) who reached the guidelines recommended for off-therapy, were followed for up to 10 years. Hepatitis B virus (HBV), viral serology and biochemistries were periodically determined. COX model was used to predict the risk of relapse. A total of 52.3% of patients experienced relapse within a median of 115 months (range, 61-122 months). A total of 93.3% of relapses occurred within 48 months. Relapse rates in hepatitis B e antigen (HBeAg)-positive (n = 56) and HBeAg-negative (n = 30) patients were 39.3% and 76.7%, respectively (p < 0.01). HBeAg-positive patients who achieved an early viral response (EVR), defined as undetectable HBV DNA within 6 months, had a lower relapse rate compared to non-EVR patients (21.4% vs. 59.2%, p < 0.01). EVR patients who had both lower HBV DNA (<10(6) copies/mL) at baseline and lower hepatitis B surface antigen (HBsAg) at end of treatment had a relapse rate of 10.7%. The high relapse rates in CHB patients over this 10-year follow-up make LAM or LdT off therapy infeasible in most of the cases, except in the case of HBsAg loss and/or seroconversion. HBeAg-positive patients with EVR, lower HBV DNA and HBsAg had lower relapse rates and could be good candidates for off-therapy. Long-term monitoring, especially during the first 4 years, is critical for patients off-therapy.

Microstructure, mechanical properties and superelasticity of biomedical porous NiTi alloy prepared by microwave sintering.

Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The results showed that the porosities and average pore sizes of the porous NiTi alloys increased with increasing the contents of NH4HCO3. The porous NiTi alloys consisted of nearly single NiTi phase, with a very small amount of two secondary phases (Ni3Ti, NiTi2) when the porosities are lower than 50%. The amount of Ni3Ti and NiTi2 phases increased with further increasing of the porosity proportion. The porosities had few effects on the phase transformation temperatures of the porous NiTi alloys. By increasing the porosities, all of the hardness, compressive strength, elastic modulus, bending strength and superelasticity of the porous NiTi alloys decreased. However, the compressive strength and bending strength were higher or close to those of natural bone and the elastic modulus was close to the natural bone. The superelastic recovery strain of the trained porous NiTi alloys could reach between 3.1 and 4.7% at the pre-strain of 5%, even if the porosity was up to 62%. Moreover, partial shape memory effect was observed for all porosity levels under the experiment conditions. Therefore, the microwave sintered porous NiTi alloys could be a promising candidate for bone implant.

Amorphous cobalt hydroxide with superior pseudocapacitive performance.

Cobalt hydroxide (Co(OH)2) has received extensive attention for its exceptional splendid electrical properties as a promising supercapacitor electrode material. Co(OH)2 study so far prefers to crystal instead of amorphous, in spite of amorphous impressive electrochemical properties including the ability to improve the electrochemical efficiency based on the disorder structure. The amorphous Co(OH)2 nanostructures with excellent electrochemical behaviors were successfully synthesized by a simple and green electrochemistry. Our as-prepared Co(OH)2 electrode exhibited ultrahigh capacitance of 1094 F g(-1) and super long cycle life of 95% retention over 8000 cycle numbers at a nominal 100 mV s(-1) scan rate. The united pseudo-capacitive performances of the amorphous Co(OH)2 nanostructures in electrochemical capacitors are totally comparable to those of the crystalline Co(OH)2 nanomaterials. These findings actually open a door to applications of amorphous nanomaterials in the field of energy storage as superior electrochemical pseudocapacitors materials.

Amorphous nickel hydroxide nanospheres with ultrahigh capacitance and energy density as electrochemical pseudocapacitor materials.

Among numerous active electrode materials, nickel hydroxide is a promising electrode in electrochemical capacitors. Nickel hydroxide research has thus far focused on the crystalline rather than the amorphous phase, despite the impressive electrochemical properties of the latter, which includes an improved electrochemical efficiency due to disorder. Here we demonstrate high-performance electrochemical supercapacitors prepared from amorphous nickel hydroxide nanospheres synthesized via simple, green electrochemistry. The amorphous nickel hydroxide electrode exhibits high capacitance (2,188 F g(-1)), and the asymmetric pseudocapacitors of the amorphous nickel hydroxide exhibit high capacitance (153 F g(-1)), high energy density (35.7 W h kg(-1) at a power density of 490 W kg(-1)) and super-long cycle life (97% and 81% charge retentions after 5,000 and 10,000 cycles, respectively). The integrated electrochemical performance of the amorphous nickel hydroxide is commensurate with crystalline materials in supercapacitors. These findings promote the application of amorphous nanostructures as advanced electrochemical pseudocapacitor materials.

[The distribution and changes of lectin receptors in developing mouse cornea].

Using ConA-HRP and RCAI-HRP as probes, the distribution and changes of glycosides in mouse cornea were studied during pre- and postnatal development. Mannose residues were distributed mainly in stroma and endothelium, sialic acid residues in epithelium and galactose residues in both epithelium and stroma. Mannose residues in stroma showed an increased density toward endothelium before and after birth. Sialic acid and galactose residues were concentrated gradually at the corneal epithelial surface in accompanied with the development of cornea. The embryonic day 13 was the starting day to synthesize glycoconjugates from fibroblasts of mouse cornea.

[Ultracytochemical studies on glycosaminoglycans during early corneal development in Bufo raddei].

Glycosaminoglycans (GAGs) and their changes in early corneal development of Bufo raddei Strauch (from stage 16, neural tube, to stage 25, operculum completely closed) were studied with electron microscopic cytochemical method. Results show that synthesis of GAGs changes from non-sulfated to sulfated, and its content increased gradually with the development of cornea. Hyaluronic acid (HA) in each part of cornea begins to increase gradually from stage 16 to 21 (mouth open stage), with its peak at stage 20 (gill circulation stage) to 21, then decreases. In the mean time, contents of dermatam sulfate (DS), chondroitin sulfate (CS), heparan sulfate (HS) and heparin (Hep) increase gradually. It is considered that HA, HS and collagen may be related to the migration of mesenchymal cells, and HA promotes the expansion and hydration of corneal stroma; sulfated GAGs are correlated with dehydration of cornea, cell density and corneal transparency; DS, CS, HS and Hep deposited among collagen fibrils could adjust their arrangement. All these changes would enhance transparency of cornea.

[Studies on the differentiation of the retina receptor cell of toad (Bufo raddei Strauch)].

The development of the retinal receptor cell in the young tadpoles (Bufo raddei Strauch), from the stage 20 to the stage 25, was studied by TEM and immunohistochemical method. The morphological differentiation of the photoreceptor cell may be described as follows. The time and the degree of differentiation of the cells in the tadpole retina is asynchronous between central (posterior pole) and peripheral parts of the tadpole retina, namely, they are earlier and higher in the central than in the peripheral. The cells of the outer nuclear layer are undifferentiated at the stage 20. The cells in the posterior part of the retina elongate at the beginning of the stage 21 (Plate I, Fig. 1). This is the first sign of differentiation in the photoreceptor cell. A small hillock-like process forms the inner segment at the scleral pole of the receptor cell. The inner segment is rich in mitochondria, rough-surfaced cytomembrane, free ribosomes, and vesicles. One or two large lipid droplets are also found in the inner segment (Plate I Fig. 2-3). Later on, the connecting structure develops at the tip of the inner segment. The newly formed filaments and the plasma membrane form the outer segment. Its membrane forms some evaginations oriented perpendicularly to the longitudinal axis of the receptor cell. In this way, disks of the outer segment are formed (Plate I Fig. 4-5). The length of the outer segment gradually increases with the number of disks increasing at the base. At the same time, an axon process of receptor cell, extending vitreal, develops synapses with dendrites of the bipolar cell in the outer plexiform layer. At the beginning (the stage 22), the synaptic structure is an immature form that lacks synaptic ribbons and vesicles (Plate II Fig. 8). Later on, ribbons and vesicles are observed in the further developed synaptic structure (Plate II Fig. 9). The toad rhodopsin was prepared by a method of Dewey et al. (1969) and Papermaster & Dreyer (1974) with slight modification. A specific immune serum against the toad rhodopsin was produced in rabbits. Using the indirect Coon's antibody technique, the localization of the rhodopsin antibody and the time when the antibody was seen in the retina of the early developing tadpoles was traced.(ABSTRACT TRUNCATED AT 400 WORDS)