Sustainable, High-Performance, and Biodegradable Plastics Made from Chitin

A high-performance biodegradable plastic was made from a chitin KOH/urea solution. The solution was transferred into a hydrogel by cross-linking using epichlorohydrin and ethanol immersion, and a chitin bioplastic was finally prepared by drying in a mold at 40 °C. The solution concentration positively impacts viscosity, crystallinity, and smoothness. A 4% chitin bioplastic exhibits high barrier properties, flame retardancy, high-temperature resistance, mechanical properties (tensile strength up to 107.1 MPa), and soil degradation properties. The chitin bioplastic can be completely degraded by microorganisms in 7 weeks. In addition, biosafety tests suggest that chitin is safe for cells and crops (wheat and mung beans). The chitin bioplastic was further applied to containers, straws, cups, and photoprotection, and it was found that the water resistance and transparency were comparable to those of commercial polypropylene plastics. Due to the excellent performance, safety, and sustainability of the chitin bioplastic, it is expected to become a good substitute for conventional fossil fuel-based plastics

Sustainable, High-Performance, and Biodegradable Plastics Made from Chitin

A high-performance biodegradable plastic was made from a chitin KOH/urea solution. The solution was transferred into a hydrogel by cross-linking using epichlorohydrin and ethanol immersion, and a chitin bioplastic was finally prepared by drying in a mold at 40 °C. The solution concentration positively impacts viscosity, crystallinity, and smoothness. A 4% chitin bioplastic exhibits high barrier properties, flame retardancy, high-temperature resistance, mechanical properties (tensile strength up to 107.1 MPa), and soil degradation properties. The chitin bioplastic can be completely degraded by microorganisms in 7 weeks. In addition, biosafety tests suggest that chitin is safe for cells and crops (wheat and mung beans). The chitin bioplastic was further applied to containers, straws, cups, and photoprotection, and it was found that the water resistance and transparency were comparable to those of commercial polypropylene plastics. Due to the excellent performance, safety, and sustainability of the chitin bioplastic, it is expected to become a good substitute for conventional fossil fuel-based plastics

Sustainable, High-Performance, and Biodegradable Plastics Made from Chitin

A high-performance biodegradable plastic was made from a chitin KOH/urea solution. The solution was transferred into a hydrogel by cross-linking using epichlorohydrin and ethanol immersion, and a chitin bioplastic was finally prepared by drying in a mold at 40 °C. The solution concentration positively impacts viscosity, crystallinity, and smoothness. A 4% chitin bioplastic exhibits high barrier properties, flame retardancy, high-temperature resistance, mechanical properties (tensile strength up to 107.1 MPa), and soil degradation properties. The chitin bioplastic can be completely degraded by microorganisms in 7 weeks. In addition, biosafety tests suggest that chitin is safe for cells and crops (wheat and mung beans). The chitin bioplastic was further applied to containers, straws, cups, and photoprotection, and it was found that the water resistance and transparency were comparable to those of commercial polypropylene plastics. Due to the excellent performance, safety, and sustainability of the chitin bioplastic, it is expected to become a good substitute for conventional fossil fuel-based plastics

Chirality-Mediated Mechanical and Structural Properties of Oligopeptide Hydrogels

The origin and the effects of homochirality in the biological world continuously stimulate numerous hypotheses and much debate. This work attempts to look at the biohomochirality issue from a different anglethe mechanical properties of the bulk biomaterial and their relation to nanoscale structures. Using a pair of oppositely charged peptides that co-assemble into hydrogels, we systematically investigated the effect of chirality on the mechanical properties of these hydrogels through different combinations of syndiotactic and isotactic peptides. It was found that homochirality confers mechanical advantage, resulting in a higher elastic modulus and strain yield value. Yet, heterochirality confers kinetic advantage, resulting in faster gelation. Structurally, both homochiral and heterochiral hydrogels are made of fibers interconnected by lappet-like webs, but the homochiral peptide fibers are thicker and denser. These results highlight the possible role of biohomochirality in the evolution and/or natural selection of biomaterials

Forced expression of exogenous HuD selectively enhanced expression of BDNF long 3′UTR mRNA in primary cultured neurons.

<p>E17 cortical neurons were cultured for 2 days and then infected with HSV-HuD or HSV-lacZ virus. Following 3 days in culture, the levels of long 3′UTR BDNF mRNA and pan BDNF mRNA were determined by qRT-PCR using primers specific in the long 3′UTR (A) and primers in the coding region that detects the pan BDNF mRNA (B). *p<0.05 (Student's t-test, n = 4).</p

A new flavonoid glycoside from <i>Elsholtzia bodinieri</i>

<p>A new flavonoid glycoside, eriodictyol 7-<i>O</i>-(6″-caffeoyl)-<i>β</i>-<i>D</i>-glucopyranoside (<b>1</b>), along with 14 known compounds, were isolated from the whole plants of <i>Elsholtzia bodinieri</i>. All of the structures were determined by spectroscopic methods and chemical transformation. Compound <b>1</b> and luteolin (<b>9</b>) exhibited potent anti-HCV activities with a selective index of 135.85 and 20.84, respectively.</p

Sedative drugs used for mechanically ventilated patients in intensive care units: a systematic review and network meta-analysis

<p><b>Background:</b> The effects of different sedative drugs on all-cause mortality rate, duration of ICU stay, and risk of delirium in mechanically ventilated ICU patients are unclear. This meta-analysis aimed to compare the effectiveness and safety of individual sedative drugs and drug combinations in mechanically ventilated ICU patients.</p> <p><b>Materials and methods:</b> Medline, Embase, Cochrane, EBSCOhost, and ISI Web of Science databases were searched for studies that assessed sedation in ICU mechanically ventilated patients. A Bayesian random-effects model was used to combine the direct comparisons and indirect evidence.</p> <p><b>Results:</b> Thirty-one randomized, controlled trials were included, which consisted of 4491 patients who received one of seven sedative drugs or a combination of drugs. There were no significant differences regarding the all-cause mortality rate. Compared to propofol, inhalation anesthetics (hazard ratio [HR] 0.121; 95% credible interval [CrI] -7.58 to 7.62), alpha agonists (HR 2.2; 95% CrI 0.776 to 5.22), propofol with benzodiazepines (HR 0.306; 95% CrI -6.97 to 7.65), ketamine with benzodiazepines (HR 6.57; 95% CrI -6.05 to 19.1) and placebo (HR 2.4; 95% CrI -5.37 to 10.3), benzodiazepines (HR 3.62; 95% CrI 0.834 to 6.2) may increase the duration of ICU stay. Compared to alpha agonists, propofol (HR 2.4; 95% CrI 0.304 to 21.1) and placebo (HR 6.12; 95% CrI 0.745 to 54.6), benzodiazepines (HR 2.59; 95% CrI 1.08 to 7.4) were associated with incremental risks of delirium.</p> <p><b>Conclusion:</b> Compared to propofol, benzodiazepines may increase the duration of ICU stay. Compared to alpha agonists, benzodiazepines were associated with an increased risk of delirium.</p

HuD enhances luciferase reporter expression through an ARE in the BDNF long 3′UTR.

<p>(A) A highly conserved cluster of Class I ARE in the BDNF long 3′UTR, with a consensus core sequence of <i>AUUUA</i> flanked by symmetric A or U (underlined). Triangles indicate alternative polyadenylation sites in the BDNF primary transcript. Primers used for RT-PCR to detect reporter mRNAs are illustrated underneath. (B) RT-PCR using multiple primers illustrated in (A) confirms expression of the expected RNA sequence from each transfected reporter construct. (C) Immunoblot (IB) showing expression of myc-HuD in the input (Inp) of transfected CAD cells and successful immunoprecipitation (IP) of myc-HuD. Two different anti-myc antibodies were used for IP and IB. (D) CLIP-qRT-PCR quantification of reporter mRNAs co-immunoprecipitated with HuD relative to the corresponding mRNA levels in the input. * indicates P<0.05 by Student's t-test (n = 3). Due to the presence of endogenous BDNF mRNA, primers specific for the luciferase coding region were used to detect reporter mRNAs. BDNF long 3′UTR reporter mRNA is preferentially enriched over short 3′UTR mRNA in immunoprecipitated HuD complex. Deletion of the ARE in the long 3′UTR significantly reduced the association or reporter mRNA with HuD.</p

Binding of HuD to the ARE in the BDNF-long 3′UTR increases the stability of the mRNA.

<p>(A) Specific binding of HuD to the ARE in BDNF-long 3′UTR was demonstrated by REMSA using recombinant proteins and radiolabeled RNA along with a 10-fold molar excess of cold ARE competitor. (B) In vitro decay assay of capped and polyadenylated RNA containing the BDNF-ARE with left lane showing RNA molecular weight markers. Analysis of the rate of decay in three independent experiment revealed that the mRNA is stabilized in the presence of HuD. Half-life for GST-treated mRNA is 7.0±0.90 min, and for GST-HuD-treated mRNA is 12.0±1.0 min. ** indicates p<0.05 by Two way ANOVA with a quantitative factor (n = 3 separate experiments).</p

HuD knockdown reduced the levels of endogenous BDNF long 3′UTR mRNA.

<p>(A) siRNA knockdown of HuD in transfected CAD cells measured by qRT-PCR using a HuD-specific primer flanking the target site by the siRNA. (B) Reduction of endogenous BDNF long 3′UTR mRNA in CAD cells measured by qRT-PCR as a result of HuD knockdown. For (A) and (B), results were derived from 3 independent experiments (n = 3), * indicates P<0.05. (C) Representative confocal images of L-BDNF FISH (red) in E17 hippocampal neurons transfected with either pEGFP control vector or pEGFP-shHuD plasmid. The transfected cells was marked by the green fluorescence and the number of FISH grains were counted in the cell bodies and processes (n = 6 for each condition) and graphically displayed in (D). Arrows mark the FISH grains in the processes. Note that the number of ISH grains in the shHuD- treated cells decreased throughout the soma and neurite relative to control GFP-vector treated cells.</p