Circularly polarized light emission and detection by chiral inorganic semiconductors.

Chiral inorganic semiconductors with high dissymmetric factor are highly desirable, but it is generally difficult to induce chiral structure in inorganic semiconductors because of their structure rigidity and symmetry. In this study, we introduced chiral ZnO film as hard template to transfer chirality to CsPbBr3 film and PbS quantum dots (QDs) for circularly polarized light (CPL) emission and detection, respectively. The prepared CsPbBr3/ZnO thin film exhibited CPL emission at 520 nm and the PbS QDs/ZnO film realized CPL detection at 780 nm, featuring high dissymmetric factor up to around 0.4. The electron transition based mechanism is responsible for chirality transfer.

Copper-catalyzed asymmetric C(sp2)-H arylation for the synthesis of P- and axially chiral phosphorus compounds.

Transition metal-catalyzed C-H bond functionalization is an important method in organic synthesis, but the development of methods that are lower cost and have a less environmental impact is desirable. Here, a Cu-catalyzed asymmetric C(sp2)-H arylation is reported. With diaryliodonium salts as arylating reagents, a range of ortho-arylated P-chiral phosphonic diamides were obtained in moderate to excellent yields with high enantioselectivities (up to 92% ee). Meanwhile, enantioselective C-3 arylation of diarylphosphine oxide indoles was also realized under similar conditions to construct axial chirality.

Regulation of Mitochondria on Platelet Apoptosis and Activation / 中国实验血液学杂志

OBJECTIVE@#To explore the regulation of mitochondria on platelet apoptosis and activation, and the relationship between platelet apoptosis and activation.@*METHODS@#Platelets were isolated from peripheral venous blood of healthy volunteers. Cyclosporin A (CsA), which has a protective effect on the function of platelet mitochondria, BAPTA, which can chelate calcium ions across membranes in platelets, and NAC, an antioxidant that reduces the level of intracellular reactive oxygen species, were selected for coincubation with washed platelets, respectively. By flow cytometry, platelet aggregator was used to detect the changes of platelet mitochondrial function and platelet activation indexes after different interventions.@*RESULTS@#H89, staurosporine, and A23187 led to platelet mitochondrial abnormalities, while CsA could effectively reverse the decline of platelet mitochondrial membrane potential caused by them. Antioxidant NAC could reverse platelet mitochondrial damage correspondingly, and completely reverse platelet shrinkage and phosphatidylserine eversion induced by H89. BAPTA, prostaglandin E1, acetylsalicylic acid and other inhibitors could not reverse the decline of platelet mitochondrial membrane potential.@*CONCLUSION@#Mitochondrial function plays an important role in platelet apoptosis and activation. Abnormal mitochondrial function causes the imbalance of reduction/oxidation state in platelets, which leads to platelet apoptosis. Platelet apoptosis and activation are independent signal processes.

Research Progress on Application of Ultrasonic Microbubbles in Treatment of Liver Cancer / 肿瘤防治研究

Ultrasound therapy and considerable progress in molecular imaging technologies have allowed the use of ultrasonic microbubbles not only in image enhancement but also in targeted drug or gene delivery as drug or gene carriers, respectively. Hence, ultrasound microbubbles carrying drugs or genes have become a novel type of tumor-targeting therapy technology. They do not emit radiation and are thus safe. Additionally, they are efficient and easy to reuse and facilitate drug or gene release. All these features offer attractive prospects for the treatment of liver cancer and provide novel treatment ideas for the disease. This article reviews the mechanism, applications, and existing problems of ultrasonic microbubbles in the treatment of liver cancer.

In situ constructed oxygen-vacancy-rich MoO3-x /porous g-C3N4 heterojunction for synergistically enhanced photocatalytic H2 evolution.

A simple method was developed for enhanced synergistic photocatalytic hydrogen evolution by in situ constructing of oxygen-vacancy-rich MoO3-x /porous g-C3N4 heterojunctions. Introduction of a MoO3-x precursor (Mo(OH)6) solution into g-C3N4 nanosheets helped to form a porous structure, and nano-sized oxygen-vacancy-rich MoO3-x in situ grew and formed a heterojunction with g-C3N4, favorable for charge separation and photocatalytic hydrogen evolution (HER). Optimizing the content of the MoO3-x precursor in the composite leads to a maximum photocatalytic H2 evolution rate of 4694.3 µmol g-1 h-1, which is approximately 4 times higher of that of pure g-C3N4 (1220.1 µmol g-1 h-1). The presence of oxygen vacancies (OVs) could give rise to electron-rich metal sites. High porosity induced more active sites on the pores' edges. Both synergistically enhanced the photocatalytic HER performance. Our study not only presented a facile method to form nano-sized heterojunctions, but also to introduce more active sites by high porosity and efficient charge separation from OVs.

Atomically thin two-dimensional ZnSe/ZnSe(ea)x van der Waals nanojunctions for synergistically enhanced visible light photocatalytic H2 evolution.

Two-dimensional (2D) photocatalysts have been widely studied due to their short charge carrier migration pathways and tunable electronic structures. Herein, a facile one-pot solvothermal process with ethylamine (ea) constructs a novel 2D nanojunction based on ZnSe. The ea molecules coordinate with Zn2+ to form 2D ZnSe(ea)x, where the consequent 2D ZnSe grows in an epitaxial way resulting in the self-assembled 2D/2D ZnSe/ZnSe(ea)x nanojunctions driven by van der Waals (VDW) force, which largely extend the absorption range. The atomic thickness of the 2D structure offers a short charge migration pathway, low electric resistance and rich active sites for the surface reaction of photocatalysis. All the above favorable factors work synergistically to reach a superior hydrogen evolution of 2875 µmol g-1 h-1 under visible light irradiation (≥420 nm) and a notable quantum yield of 64.5% at 450 nm, which are among the highest recorded values of non-noble metal photocatalysts.

Circularly polarized light detection using chiral hybrid perovskite.

Circularly polarized light (CPL) detection is required in various fields such as drug screening, security surveillance and quantum optics. Conventionally, CPL photodetector needs the installation of optical elements, imposing difficulties for integrated and flexible devices. The established CPL detectors without optical elements rely on chiral organic semiconductor and metal metamaterials, but they suffer from extremely low responsivity. Organic-inorganic hybrid materials combine CPL-sensitive absorption induced by chiral organics and efficient charge transport of inorganic frameworks, providing an option for direct CPL detection. Here we report the CPL detector using chiral organic-inorganic hybrid perovskites, and obtain a device with responsivity of 797 mA W-1, detectivity of 7.1 × 1011 Jones, 3-dB frequency of 150 Hz and one-month stability, a competitive combined feature for circularly polarized light detection. Thanks to the solution processing, we further demonstrate flexible devices on polyethylene terephthalate substrate with comparable performance.

Aqueous Synthesis of Lead Halide Perovskite Nanocrystals with High Water Stability and Bright Photoluminescence.

Lead halide perovskite nanocrystals (NCs) have attracted intense attention because of their excellent optoelectronic properties. The ionic nature of halide perovskites makes them highly vulnerable to water. Encapsulation of perovskite NCs with inorganic or organic materials has been reported to enhance their stability; however, they often suffer from large aggregation size, low water solubility, and difficulty for further surface functionalization. Here, we report a facile aqueous process to synthesize water-soluble CsPbBr3/Cs4PbBr6 NCs with the assistance of a fluorocarbon agent (FCA), which features a novel mechanism of the perovskite crystallization at the oil/water interface and direct perovskite NCs/FCA self-assembly in an aqueous environment. The products exhibit a high absolute photoluminescence quantum yield (PLQY) of ∼80% in water with the PL lasting for weeks. Through successive ionic layer adsorption and reaction, BaSO4 was further applied to encapsulate the NCs, which greatly enhanced their stability in phosphate-buffered saline solutions. The high stability in water and saline solution, high PLQY, and tunable emission wavelength, together with the successful demonstration of brain tissue labeling and PL under X-ray excitation, make our perovskite NCs a promising choice for X-ray fluorescent biolabels.

Versatile Solution-Processed Synthesis of Two-Dimensional Ultrathin Metal Chalcogenides Following Frank-van der Merwe Growth.

Two-dimensional (2D) ultrathin metal chalcogenides represent a class of promising materials for various applications thanks to attractive physicochemical properties. However, a reliable pathway for fabricating ultrathin metal chalcogenides nanosheets, regardless of the bulk crystals of their 3D counterparts, still remains a challenge. Herein, we present a versatile solution-processed template synthesis strategy, in which a single molecular-level precursor anneals to ultrathin single-crystal nanosheets with the aid of lattice-matching templates, following the Frank-van der Merwe growth mode and featuring high quality, low cost, scalability, and processability. Following this strategy, Sb2S3, MoS2, and ZnS nanosheets are successfully prepared as representatives for materials whose bulk counterparts possess 1D, 2D, and 3D crystal structures, respectively, and the growth mechanism is confirmed by crystal mode analysis. As a proof-of-concept application, MoS2 and Sb2S3 nanosheets are used for gas sensor and flexible photodetector applications, respectively, which exhibit excellent performance. The method can also be easily extended to other ultrathin nanosheets like single metals, metal oxide, metal nitride, and heterostructures.

Direct Aqueous Dispersion of Carbon Nanotubes Using Nanoparticle-Formed Fullerenes and Self-Assembled Formation of p/n Heterojunctions with Polythiophene.

Single-walled carbon nanotubes (SWCNTs) have received much attention because of their potential in optoelectronic applications. Pristine SWCNTs exhibit substantial van der Waals interactions and hydrophobic characteristics, so precipitation occurs immediately in most organic solvents and water. Highly toxic and hazardous chemicals are often used to obtain well-dispersed SWCNTs. Developing environmentally friendly processing methods for safe and practical applications is a great challenge. Here, we demonstrate direct exfoliation of SWCNTs in pure water only with n-type semiconducting fullerene nanoparticles. The resultant SWCNTs can be well-dispersed in water, where they remain essentially unchanged for several weeks. Adding an aqueous solution of p-type semiconducting water-soluble polythiophene yields self-assembled p/n heterojunctions between polythiophene and the nanoparticles. The aqueous-dispersed SWCNTs yield photocurrent responses in solution-processed thin films as a potential application of water-dispersed carbon nanomaterials.

Lead-Free, Blue Emitting Bismuth Halide Perovskite Quantum Dots.

Lead halide perovskite quantum dots (QDs) are promising candidates for future lighting applications, due to their high quantum yield, narrow full width at half maximum (FWHM), and wide color gamut. However, the toxicity of lead represents a potential obstacle to their utilization. Although tin(II) has been used to replace lead in films and QDs, the high intrinsic defect density and oxidation vulnerability typically leads to unsatisfactory material properties. Bismuth, with much lower toxicity than lead, is promising to constitute lead-free perovskite materials because Bi3+ is isoelectronic to Pb2+ and more stable than Sn2+ . Herein we report, for the first time, the synthesis and optical characterization of MA3 Bi2 Br9 perovskite QDs with photoluminescence quantum yield (PLQY) up to 12 %, which is much higher than Sn-based perovskite nanocrystals. Furthermore, the photoluminescence (PL) peaks of MA3 Bi2 X9 QDs could be easily tuned from 360 to 540 nm through anion exchange.

Solubilization of single-walled carbon nanotubes using a peptide aptamer in water below the critical micelle concentration.

The solubilizing ability of single-walled carbon nanotubes (SWCNTs) in water with several dispersants was investigated. Among the dispersants, including low-molecular-weight surfactants, peptides, DNA, and a water-soluble polymer, the peptide aptamer, A2 (IFRLSWGTYFS), exhibited the highest dispersion capability below the critical micelle concentration at a concentration of 0.02 w/v%. The dispersion of supernatant aqueous solution of SWCNTs containing aptamer A2 was essentially unchanged for several months after high-speed ultracentrifugation and gave rise to an efficient and stable dispersion of the SWCNTs in water. From the results of isothermal titration calorimetry and molecular dynamics simulations, the effective binding capability of A2 was due to π-π interaction between aromatic groups in the peptide aptamer and the side walls of SWCNTs. Interestingly, the peptide aptamer showed the possibility of diameter separation of semiconducting SWCNTs using a uniform density gradient ultracentrifuge. These phenomena are encouraging results toward an effective approach to the dispersion and separation of SWCNTs.

The target adjustment of the end-tidal carbon dioxide partial pressure in preterm infants under mechanical ventilation / 中华实用儿科临床杂志

Objective To reduce the incidence of the hypocapnia,the cutoff value of the end-tidal carbon dioxide partial pressure[Pet(CO2)] for predicting the hypocapnia so as to understand the suitable adjustment target and target range of the Pet(CO2) in preterm infants under mechanical ventilation.Methods From Jan.2012 to Oct.2013,96 cases of the preterm infants with respiratory distress syndrome(RDS) who needed mechanical support were selected from the Huaian Maternity and Child Health Care Hospital.Pet(CO2) value of each time point(1 h,24 h,48 h and 72 h after mechanical ventilation) were recorded,while radial artery blood was collected for blood gas analysis.The level of pa (CO2) ＜ 35 mmHg(1 mmHg =0.133 kPa) diagnosed hypocapnia;while the level of Pa (CO2) ＞ 60 mmHg was for diagnosing hypercapnia.The diagnostic cutoff and the suitable adjustment target and adjustment target range of the Pet(CO2) were confirmed by receiver operating characteristic (ROC) curve.Results The data from 381 arterial blood gas analysis results were gained,of which 151 times belonged to hypocapnia,and the rate was 39.6％,the other 230 cases were normal,and no case was of hypercapnia.The area under the ROC curve was 0.895,and the area of the standard error was 0.016.There was a statistical significance in Pet(CO2) value for the diagnosis of hypocapnia(P =0.000).The lower the value of Pet (CO2),the greater the likelihood of hypocapnia,and 95 ％ confidence interval area was 0.864-0.926.The Pet (CO2) optimal diagnostic cutoff value determined in accordance with Youden index was 30.5 mmHg.When Pet (CO2) among 41.5 mmHg,sensitivity was 100％.Conclusions Diagnostic cutoff value for forecasting hypocapnia is 30.5 mmHg.The suitable adjustment target of mechanical ventilation parameter adjustment is 41.5 mmHg for the Pet(CO2).The target range of mechanical ventilation parameter adjustment is 30.6-41.5 mmHg for the Pet(CO2).

Detection of soluble triggering receptor expressed on myeloid cell-1 for diagnosis of early-onset neonatal sepsis / 中华临床感染病杂志

Objective To assess the clinical value of serum soluble triggering receptor expressed on myeloid cell-1 (sTREM-1) for diagnosis of early-onset neonatal sepsis (EONS).Methods A total of 90 neonatal cases with risk factors or symptoms of bacterial infections were enrolled in the study.All infants were admitted to Huai' an Maternity and Child Healthcare Hospital within 24 h after birth during January and June 2014.The enrolled neonates were divided into sepsis group (n =33),general infection group (n =23) and non-infected group (n =34);and the sepsis group was further divided into culture-confirmed group (n =6) and clinical-diagnosed group (n =27).Twenty healthy neonates were also enrolled as the healthy control group.Blood samples were obtained from neonatal patients on d1,d3 and d7 after birth,and for healthy controls,the blood samples were only obtained at the first day.Serum levels of sTREM-1 and interleukin (IL)-6 were measured by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA).The receiver operating characteristic (ROC) curve was applied to evaluate the values of sTREM-1 and IL-6 in diagnosis of EONS.Results Compared with that in general infection group,non-infected group and healthy control group,the serum level of sTREM-1 was significantly higher in sepsis group (all P ＜ 0.05);serum levels of sTREM-1 in general infection group and non-infected group were also higher than that in healthy control group (all P ＜ 0.05);but no difference was observed between general infection group and non-infected group,between culture-confirmed group and clinical-diagnosed group (P ＞ 0.05).Serum level of sTREM-1 showed upward trend during d1-3 after the birth,and downward trend during d3-7.The areas under the ROC curve (AUC) were 0.810 and 0.811 (all P ＜ 0.05) for sTREM-1 levels on d1 and d3 in diagnosis of EONS,and the optimal cut-off values were 234.44 ng/L and 269.79 ng/L,respectively.If sTREM-1 and IL-6 on d1 were combined for diagnosis of EONS,the AUC,sensitivity and specificity were 0.858,92.00％ and 93.10％,respectively.Conclusion Serum level of sTREM-1 in early stage is valuable for diagnosis of EONS,and the combined use of serum sTREM-1 and IL-6 may improve the diagnostic value.

Predictive value of Downes score on respiratory failure in term neonates / 中华围产医学杂志

Objective To explore the clinical significance of Downes score in predicting respiratory failure (RF) in term neonates.Methods From June 1, 2011 to December 31, 2013, 243 hospitalized term neonates with dyspnea, who were born at 37 to 42 gestational age and admitted to the hospital within 24 h after birth, were selected from Neonatal Medical Center of Huai'an Maternity and Child Healthcare.Downes scores were evaluated based on five indicators including respiratory rate, skin color, three depressions sign, moaning and lung breath sounds at the time of admission.RF was diagnosed based on clinical menifestations and radial arterial blood gas analysis.Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of Downes score on RF.Results The average Downes score of the 243 cases was 6.57±0.86 and the RF rate was 69.6％ (169/243).The RF rate was 93.4％ (169/181) when Downes score ≥ 4.5, with the sensitivity, specificity, misdiagnostic rate and missed diagnositic rate of 100.0％, 83.8％, 16.2％ and 0.0％, respectively.While, the RF rate was 80.7％ (130/161) when Downes score ≥ 5.5, with the sensitivity, specificity, misdiagnostic rate and missed diagnositic rate of 76.9％, 58.1％, 41.9％ and 23.1％, respectively.When Downes score ≥ 6.5, the incidence of RF was 97.6％ (123/126), with the sensitivity, specificity, misdiagnositic rate and missed diagnositic rate of 72.8％, 95.9％, 4.1％ and 27.2％, respectively.The cutoff value was 6.5 according to the Youden Index, which with lower rate of misdiagnosis and missed diagnosis.When Downes score ≥ 7.5, the incidence of RF was 100.0％(22/22), with the sensitivity, specificity, misdiagnositic rate and missed diagnosis rate of 13.1％, 100.0％, 0.0％ and 87.0％, respectively.The area under the ROC curve was 0.906 (95％CI: 0.866-0.955).The higher the Downes score, the greater the possibility of RF (P=0.000).Conclusions Dynamic Downes scores in term neonates with dyspnea could predict the risk of RF.The higher the Downes score, the greater the possibility of RF.

In vitro selection of peptide aptamers using a ribosome display for a conducting polymer.

Ribosome display was used to select peptide aptamers from a random library composed of hydrophilic amino acids for a conducting polymer, poly(3-hexylthiophene-2,5-diyl). Binding of aptamers was measured by quartz crystal microbalance, and the secondary structure of the peptide was investigated by circular dichroism.

Application of lung recruitment maneuver in preterm infants with respiratory distress syndrome ventilated by proportional assist ventilation / 中华儿科杂志

<p><b>OBJECTIVE</b>To understand the effect of lung recruitment maneuver (LRM) with positive end-expiratory pressure (PEEP) on oxygenation and outcomes in preterm infants with respiratory distress syndrome (RDS) ventilated by proportional assist ventilation (PAV).</p><p><b>METHOD</b>From January 2012 to June 2013, thirty neonates with a diagnosis of RDS who required mechanical ventilation were divided randomly into LRM group (n=15, received an LRM and surport by PAV) and control group (n=15, only surport by PAV). There were no statistically significant differences in female (7 vs. 6); gestational age [(29.3±1.2) vs. (29.5±1.1) weeks]; body weight[(1,319±97) vs. (1,295±85) g]; Silverman Anderson(SA) score for babies at start of ventilation (7.3±1.2 vs. 6.9±1.4); initial FiO2 (0.54±0.12 vs. 0.50±0.10) between the two groups (all P>0.05). LRM entailed increments of 0.2 cmH2O (1 cmH2O=0.098 kPa) PEEP every 5 minutes, until fraction of inspired oxygen (FiO2)=0.25. Then PEEP was reduced and the lung volume was set on the deflation limb of the pressure/volume curve.When saturation of peripheral oxygen fell and FiO2 rose, we reincremented PEEP until SpO2 became stable. The related clinical indicators of the two group were observed.</p><p><b>RESULT</b>The doses of surfactant administered (1.1±0.3 vs. 1.5±0.5, P=0.027), Lowest FiO2 (0.29±0.05 vs. 0.39±0.06, P=0.000), time to lowest FiO2[ (103±18) vs. (368±138) min, P=0.000] and O2 dependency [(7.6±1.0) vs.( 8.8±1.3) days, P=0.021] in LRM group were lower than that in control group (all P<0.05). The maximum PEEP during the first 12 hours of life [(8.4±0.8) vs. (6.8±0.8) cmH2O, P=0.000] in LRM group were higher than that in control group (P<0.05). FiO2 levels progressively decreased (F=35.681, P=0.000) and a/AO2 Gradually increased (F=37.654, P=0.000). No adverse events and no significant differences in the outcomes were observed.</p><p><b>CONCLUSION</b>LRM can reduce the doses of pulmonary surfactant administered, time of the respiratory support and the oxygen therapy in preterm children with RDS.</p>

In vitro selection of peptide aptamers with affinity to single-wall carbon nanotubes using a ribosome display.

A ribosome display from a diverse random library was applied for selecting peptide aptamers with high binding affinity to single-wall carbon nanotubes (SWCNTs). The selected peptide aptamer bound to and solubilized SWCNTs more strongly than did the peptide aptamer selected by a phage display method reported previously, and more strongly than other commonly used organic surfactants. The fluorescence spectrum of this aptamer showed a red shift upon interaction with SWCNTs but circular dichroism spectroscopy did not show any significant difference between the presence or absence of SWCNT binding.

Stabilized ribosome display for in vitro selection.

Ribosome display is a very effective and powerful technology for screening functional peptides or polypeptides in vitro. In ribosome display, each peptide or polypeptide (phenotype) links with its corresponding mRNA (genotype) through a ribosome. This link can be achieved by the absence of a stop codon in the mRNA, therefore stalling the ribosome at the end of translation with the nascent random sequence peptide extended by a spacer outside of the ribosome tunnel. In this chapter, we describe a method for the use of a further stabilized peptide-ribosome-mRNA complex for ribosome display.

Strategy of breast reconstruction for patients with caesarotomy scar using pedicled TRAM flap / 中华医学美学美容杂志

Objective To investigate the availability and strategy of breast reconstruction for patients with caesarotomy scar using pedicled TRAM flap.Methods From January 2007 to May 2011,12 cases of breast reconstruction with caesarotomy scar were carried out with pedicled TRAM flaps.All the patients that were classified as the class Ⅱ that was 0.5 or less by score were operated on by using the inverted trapezoid incision,of which the upper edge was 2 or 3 cm down to the umbilicus.Double pedicles were adopted for the patient with the longest vertical scar; single pedicle of the breast contralateral side and the muscle sheath of the breast ipsilateral side were harvested for the rest of the patients.A synthetic mesh was used for the enforcement of the muscle and sheath defect.Results No flap necrosis or abdominal complications were observed.With the follow-up from 3 months to 4 years and 4 months,the overall satisfactory rate was 100 ％.Conclusions The strict patient selection and the operating strategy are the keys to the successful breast reconstruction for patients with caesarotomy scar using pedicled TRAM flap.