Research advances in smart responsive-hydrogel dressings with potential clinical diabetic wound healing properties

The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem.Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds due to their excellent hydrophilicity,good drug-loading ability and sustained drug release properties.As a typical example,hyaluronic acid dressing(Healoderm)has been demonstrated in clinical trials to improve wound-healing efficiency and healing rates for diabetic foot ulcers.However,the drug release and degradation behavior of clinically-used hydrogel wound dressings cannot be adjusted according to the wound microenvironment.Due to the intricacy of diabetic wounds,antibiotics and other medications are frequently combined with hydrogel dressings in clinical practice,although these medications are easily hindered by the hostile environment.In this case,scientists have created responsive-hydrogel dressings based on the microenvironment features of diabetic wounds(such as high glucose and low pH)or combined with external stimuli(such as light or magnetic field)to achieve controllable drug release,gel degradation,and microenvironment improvements in order to overcome these clinical issues.These responsive-hydrogel dressings are anticipated to play a significant role in diabetic therapeutic wound dressings.Here,we review recent advances on responsive-hydrogel dressings towards diabetic wound healing,with focus on hydrogel structure design,the principle of responsiveness,and the behavior of degradation.Last but not least,the advantages and limitations of these responsive-hydrogels in clinical applications will also be discussed.We hope that this review will contribute to furthering progress on hydrogels as an improved dressing for diabetic wound healing and practical clinical application.

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson’s disease.As such,inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson’s disease.Ginsenoside Rbl,the most active ingredient of ginseng,reportedly exerts neuroprotective effects by suppressing inflammation in vitro.The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rbl in a lipopolysaccharide-induced rat Parkinson’s disease model.Rats were divided into four groups.In the control group,sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days.In the ginsenoside Rbl group,ginsenoside Rb1(20 mg/kg)was intraperitoneally injected for 14 consecutive days after sham surgery.In the lipopolysaccharide group,a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson’s disease model.Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days.In the ginsenoside Rbl +lipopolysaccharide group,lipopolysaccharide was unilaterally microinjected into the rat substantial nigra.Subsequently,ginsenoside Rbl was intraperitoneally injected for 14 consecutive days.To investigate the therapeutic effects of ginsenoside Rbl,behavioral tests were performed on day 15 after lipopolysaccharide injection.We found that ginsenoside Rbl treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group.To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rbl,contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography.Compared with the lipopolysaccharide group,ginsenoside Rbl obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum.To further explore the neuroprotective effect of ginsenoside Rbl against lipopolysaccharide-induced neurotoxicity,immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta.The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression.However,ginsenoside Rb1 noticeably reversed these changes.To investigate whether the neuroprotective effect of ginsenoside Rbl was associated with inhibition of lipopolysaccharide-induced microglial activation,we examined expression of the microglia marker Iba-1.Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra;however,ginsenoside Rbl effectively suppressed lipopolysaccharide-induced microglial overactivation.To elucidate the inhibitory mechanism of ginsenoside Rb1,we examined expression levels of inflammatory mediators(tumor necrosis factor-a,interleukin-1β,inducible nitric oxide synthase,and cyclooxygenase 2)and phosphorylation of nuclear factor kappa B signaling-related proteins(IκB,IKK)in the substantia nigra with enzyme-linked immunosorbent and western blot assays.Our results revealed that compared with the control group,phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased;whereas,ginsenoside Rbl obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta.These findings confirm that ginsenoside Rbl can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons,which may be related to its inhibition of the nuclear factor kappa B signaling pathway.This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016(approval No.KYLL-2016-0148).

Risk factors for new onset diabetes mellitus after liver transplantation: A meta-analysis

AIM: To determine the risk factors for new-onset diabetes mellitus(NODM) after liver transplantation by conducting a systematic review and meta-analysis.METHODS: We electronically searched the databases of MEDLINE, EMBASE and the Cochrane Library from January 1980 to December 2013 to identify relevant studies reporting risk factors for NODM after liver transplantation. Two authors independently assessed the trials for inclusion and extracted the data. Discrepancies were resolved in consultation with a third reviewer. All statistical analyses were performed with the Rev Man5.0 software(The Cochrane Collaboration, Oxford, United Kingdom). Pooled odds ratios(OR) or weighted mean differences(WMD) with 95% confidence intervals(CIs) were calculated using either a fixed effects or a random effects model, based on the presence(I2 < 50%) or absence(I2 > 50%) of significant heterogeneity. RESULTS: Twenty studies with 4580 patients were included in the meta-analysis, all of which were retrospective. The meta-analysis identified the following significant risk factors: hepatitis C virus(HCV) infection(OR = 2.68; 95%CI: 1.92-3.72); a family history of diabetes(OR = 1.69, 95%CI: 1.09-2.63, P < 0.00001); male gender(OR = 1.53; 95%CI: 1.24-1.90; P < 0.0001); impaired fasting glucose(IFG; OR = 3.27; 95%CI: 1.84-5.81; P < 0.0001); a family history of diabetes(OR = 1.69; 95%CI: 1.09-2.63; P = 0.02); use of tacrolimus(OR = 1.34; 95%CI: 1.03-1.76; P = 0.03) and body mass index(BMI)(WMD = 1.19, 95%CI: 0.69-1.68, P < 0.00001). Other factors, such as hepatitis B virus infection and alcoholism, were not found to be associated with the incidence of NODM.CONCLUSION: The study showed that HCV infection, IFG, a family history of diabetes, male gender, tacrolimus and BMI are risk factors for NODM after liver transplantation.

Inspiration of the functional localization of a US naval hospital ship on a Chinese hospital ship

Through the experience of being stationed on the USS Mercy hospital ship(T-AH19) and a preliminary comprehension of the personnel and material arrangements,processing and functional formats,and the multi-platform contributions of US Navy hospital ships,we briefly introduce the characteristics of US hospital ships regarding medical support,emergency rescue exercises,communications and training,international humanitarian aid,etc.We discuss the function and responsibility of Chinese hospital ships,focusing on the investigation of the construction mode and positioning in the navy.

The 30-Day Oral Administration Studies of Liposoluble Tea Polyphenols in Rats

Tea polyphenols is a natural antioxidant with a variety of biological activity.However,the weak liposolubility and low bioavailability limit their application.As a result,structural modification of tea polyphenols comes into being.The prepared liposoluble tea polyphenols was suggested as a good candidate antioxidant for edible-oil and fats products.But,safety studies on liposoluble tea polyphenols are limited.The objective of the present study was conducted to synthesize liposoluble tea polyphenols and evaluate its toxicity in Sprague-Dawley rats on oral administration at dietary levels of 1,2 and 4% for 30 days.There were no adverse effects on general condition,growth,food intake,feed conversion efficiency,haematology parameters,clinical chemistry values and organ weights.High-dose males exhibited a higher haemoglobin concentration and a lower alanine aminotransferase levels,and high-dose females showed a lower albumin and globulin levels.These slight changes were considered of no toxicological significance.Necropsy and histopathology findings revealed no treatment-related changes in any of the organs.Thus,the results allowed us to conclude that the liposoluble tea polyphenols properly utilized in the oral administration could be devoid of any toxic risk.

Contrast-enhanced micro-computed tomography using Exi Tron nano6000 for assessment of liver injury

AIM: To explore the potential of contrast-enhanced computed tomography(CECT) using Exi Tron nano6000 for assessment of liver lesions in mouse models.METHODS: Three mouse models of liver lesions were used: bile duct ligation(BDL),lipopolysaccharide(LPS)/D-galactosamine(D-Gal N),and alcohol.After injection with the contrast agent Exi Tron nano6000,the mice were scanned with micro-CT.Liver lesions were evaluated using CECT images,hematoxylin and eosin staining,and serum aminotransferase levels.Macrophage distribution in the injury models was shown by immunohistochemical staining of CD68.The in vitro studies measured the densities of RAW264.7 under different conditions by CECT.RESULTS: In the in vitro studies,CECT provided specific and strong contrast enhancement of liver in mice.CECT could present heterogeneous images anddensities of injured livers induced by BDL,LPS/D-Gal N,and alcohol.The liver histology and immunochemistry of CD68 demonstrated that both dilated biliary tracts and necrosis in the injured livers could lead to the heterogeneous distribution of macrophages.The in vitro study showed that the RAW264.7 cell masses had higher densities after LPS activation.CONCLUSION: Micro-CT with the contrast agent Exi Tron nano6000 is feasible for detecting various liver lesions by emphasizing the heterogeneous textures and densities of CECT images.

用于风电场群规划的风电场尺度尾流模型研究

风电场的尾流最长可延伸至数十公里,上游风电场尾流会对下游风电场发电量产生显著影响。因此,在风电场建设中需要考虑风电场间尾流效应。基于工程尾流模型仿真模拟,研究了风电场在不同湍流强度以及不同排布密度下尾流区风速分布情况。提出了关于阻滞参数与湍流效应参数的双参数风电场尾流半经验数学模型。通过与我国北方某风电基地实测数据对比,结果表明:所提风电场模型模拟结果与实测结果相符合,能够较好地表达风电场尾流平均风速的变化规律,对未来大型风电基地规划有指导意义。

Association of CT perfusion imaging with plasma levels of TGF-β1 and VEGF in patients with NSCLC

Objective: To study the association of CT perfusion imaging parameters with plasma level of transforming growth factor-β1(TGF-β1) and vascular endothelial growth(VEGF) in patients with non small cell cancer(NSCLC). Methods: A total of 67 patients with NSCLC(NSCLC group) and 64 patients with benign lesion(control group) were given with CT perfusion imaging to obtain blood flow, blood volume, mean transit time, time to peal and permeability surface through CT perfusion software. The plasma levels of TGF-β1 and VEGF were tested by ELISA. The relationship between plasma levels of TGF-β1, VEGF and CT perfusion imaging parameters were analyzed. Results: CT perfusion imaging parameters and the plasma levels of TGF-β1 and VEGF of NSCLC group were significantly higher than the control group(P<0.05), while CT perfusion parameters and the levels of TGF-β1 and VEGF in NSCLC group showed significant difference in different tumor node metastasis stages(P<0.05). Correlation analysis showed that the level of plasma TGF-β1 and VEGF were positively correlated with blood flow, blood volume, and mean transit time(P<0.05), and negatively correlated with time to peal(P<0.05). There was no significant correlation between TGF-β1 and VEGF with the permeability surface. Conclusions: CT perfusion imaging parameters in patients with NSCLC is closely associated with plasma TGF-β1, VEGF and its biological characteristics. CT perfusion imaging is a convenient method to detect tumor blood perfusion.

Cyanidin suppresses amyloid beta-induced neurotoxicity by inhibiting reactive oxygen speciesmediated DNA damage and apoptosis in PC12 cells

Amyloid beta（Aβ）-induced oxidative stress is a major pathologic hallmark of Alzheimer＇s disease. Cyanidin, a natural flavonoid compound, is neuroprotective against oxidative damage-mediated degeneration. However, its molecular mechanism remains unclear. Here, we investigated the effects of cyanidin pretreatment against Aβ-induced neurotoxicity in PC12 cells, and explored the underlying mechanisms. Cyanidin pretreatment significantly attenuated Aβ-induced cell mortality and morphological changes in PC12 cells. Mechanistically, cyanidin effectively blocked apoptosis induced by Aβ, by restoring the mitochondrial membrane potential via upregulation of Bcl-2 protein expression. Moreover, cyanidin markedly protected PC12 cells from Aβ-induced DNA damage by blocking reactive oxide species and superoxide accumulation. These results provide evidence that cyanidin suppresses Aβ-induced cytotoxicity, by preventing oxidative damage mediated by reactive oxide species, which in turn inhibits mitochondrial apoptosis. Our study demonstrates the therapeutic potential of cyanidin in the prevention of oxidative stress-mediated Aβ neurotoxicity.

Advances in Research on Chemical Constituents and Their Biological Activities of the Genus Actinidia

Kiwi,a fruit from plants of the genus Actinidia,is one of the famous fruits with thousand years of edible history.In the past twenty years,a great deal of research has been done on the chemical constituents of the Actinidia species.A large number of secondary metabolites including triterpenoids,flavonoids,phenols,etc.have been identified from differents parts of Actinidia plants,which exhibited significant in vitro and in vivo pharmacological activities including anticancer,anti-inflammatory,neuroprotective,anti-oxidative,anti-bacterial,and anti-diabetic activities.In order to fully understand the chemical compo-nents and biological activities of Actinidia plants,and to improve their further research,development and utilization,this review summarizes the compounds extracted from different parts of Actinidia plants since 1959 to 2020,classifies the types of constituents,reports on the pharmacological activities of relative compounds and medicinal potentials.

Influence of bottleneck on single-file pedestrian flow:Findings from two experiments

In order to investigate the influence of bottleneck on single-file pedestrian flow,we conduct two different bottleneck experiments.The first one is on ring road,while the second one is on straight route.For the first one,the global density is always set to be 1.5 ped/m.The corresponding critical flow rate for the bottleneck activation is about 0.57 ped/s.The data of the detectors set at different locations,including the velocities and time-headways,show that the amplitude of the oscillation of the stop-and-go waves gradually increases during the upstream propagation.Besides,when the measured flow rates are the same,the different situations in the single-file experiments with and without bottleneck are compared and discussed.For the second one,lower flow rates are used and the bottleneck is always activated.In all the runs,the system can reach one stable state,and the time needed is nearly the same.Inside the stable area,the statistics of pedestrians'velocities keeps nearly constant in both time and space.Outside this area,when the waiting time is not long(X=10 s),the phenomenon observed is similar to that found on ring road,e.g.,the statistics of pedestrians'velocities also gradually increases during the upstream propagation.This phenomenon is similar to that found in vehicular traffic flow,which shows the universality of different traffic flows.But when the waiting time becomes longer(X=20 s),this situation will be broken since the actions of many pedestrians become much slower.All these results can facilitate understanding more about the influence of bottleneck on single-file pedestrian flow.

Bandwidth expansion and pulse shape optimized for 10 PW laser design via spectral shaping

We demonstrated a scheme of bandwidth expansion and pulse shape optimized to afford 10 PW laser design via spec-tral shaping,which uses the existing Nd:glass amplifier chain of the SG PW laser.Compared to the amplified pulse with a gain-narrowing effect,the required parameters of injected pulse energy,spectral bandwidth,and shape are analyzed,to-gether with their influence on the system B-integral,energy output capability,and temporal intensity contrast.A bandwidth expansion to 7 nm by using LiNbO_(3) birefringent spectral shaping resulted in an output energy of 2 kJ in a proof-of-principle experiment.The results are consistent with the theoretical prediction which suggests that the amplifier chain of SG PW laser is capable of achieving 6 kJ at the bandwidth of 7 nm and the B-integral<π.This will support a 10 PW laser with a compressed pulse energy of 4.8 kJ(efficiency=80%)at 480 fs.

Design and applications of carbon dots-based ratiometric fluorescent probes:A review

Ratiometric fluorescence(FL)probes can eliminate the background interference and provide more accurate detection results than single emission intensity-based nanoprobes.Recently,carbon dots(CDs)-based ratiometric FL probes have received extensive research attention due to their excellent biocompatibility,water solubility,and multi-emission capabilities.In this review,we firstly summarize the construction strategies of CDs-based ratiometric FL probes,including physical mixing,nanohybrid,and dual-emitting CDs strategies.Additionally,we classify the sensing types of CDs-based ratiometric FL probes into five categories according to the difference in spectral variation caused by analytes:“single-response-ON”,“single-response-OFF”,“doubleresponses-ON”,“double-responses-OFF”,and“double-responses-Reverse”types.Finally,a thorough overview of CDs-based ratiometric FL probe applications in ions,molecules,pH,and temperature sensing is provided.We believe this review can show the latest research progress of CDs-based ratiometric FL sensing fields and provide perspectives on future developments for the construction of CDs-based ratiometric FL probes and their potential applications.

The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity

The contact angle,as a vital measured parameter of wettability of material surface,has long been in dispute whether it is affected by gravity.Herein,we measured the advancing and receding contact angles on extremely low contact angle hysteresis surfaces under different gravities(1-8G)and found that both of them decrease with the increase of the gravity.The underlying mechanism is revealed to be the contact angle hysteresis and the deformation of the liquid-vapor interface away from the solid surface caused by gradient distribution of the hydrostatic pressure.The real contact angle is not affected by gravity and cannot measured by an optical method.The measured apparent contact angles are angles of inclination of the liquid-vapor interface away from the solid surface.Furthermore,a new equation is proposed based on the balance of forces acting on the three-phase contact region,which quantitatively reveals the relation of the apparent contact angle with the interfacial tensions and gravity.This finding can provide new horizons for solving the debate on whether gravity affects the contact angle and may be useful for the accurate measurement of the contact angle and the development of a new contact angle measurement system.

Erratum to“The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity”

In the article titled“The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity”[1],there were errors in Figure 2 which occurred during production.These errors are listed below,and the corrected version is shown as Figure 1.

含炔键的聚合物给体材料设计合成及在有机太阳能电池中的性能研究

利用结构简单、成本低廉的初始原料,设计合成了主链含炔键的聚合物给体材料PBEA-F和PBEA.由于炔键的强吸电子能力,分子的最高占有轨道能级(HOMO)得以降低,使得聚合物的带隙变宽.同时,引入炔键的聚合物给体材料与受体小分子材料BTP-eC9-4F共混制备有机太阳能电池器件,可实现较低的非辐射能量损失与高的开路电压(open circuit voltage,Voc).最终基于PBEA的器件可得到0.91 eV的Voc、20.70 mA/cm^(2)的短路电流密度(short-circuit current density,Jsc)和10.39%的能量转化效率(power conversion efficiency,PCE),远高于PBEA-F器件的PCE (5.50%).

A unique subseafloor microbiosphere in the Mariana Trench driven by episodic sedimentation

Hadal trenches are characterized by enhanced and infrequent high-rate episodic sedimentation events that likely introduce not only labile organic carbon and key nutrients but also new microbes that significantly alter the subseafloor microbiosphere.Currently,the role of high-rate episodic sedimentation in controlling the composition of the hadal subseafloor microbiosphere is unknown.Here,analyses of carbon isotope composition in a~750 cm long sediment core from the Challenger Deep revealed noncontinuous deposition,with anomalous ^(14)C ages likely caused by seismically driven mass transport and the funneling effect of trench geomorphology.Microbial community composition and diverse enzyme activities in the upper~27 cm differed from those at lower depths,probably due to sudden sediment deposition and differences in redox condition and organic matter availability.At lower depths,microbial population numbers,and composition remained relatively constant,except at some discrete depths with altered enzyme activity and microbial phyla abundance,possibly due to additional sudden sedimentation events of different magnitude.Evidence is provided of a unique role for high-rate episodic sedimentation events in controlling the subsurface microbiosphere in Earth’s deepest ocean floor and highlight the need to perform thorough analysis over a large depth range to characterize hadal benthic populations.Such depositional processes are likely crucial in shaping deep-water geochemical environments and thereby the deep subseafloor biosphere.

Two pairs of unusual scalemic enantiomers from Isatis indigotica leaves

Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl）ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-（4＂-hydroxy-3＂,5＂- named isatidifoliumindolinones A-D （1-4）, were isolated from an aqueous extract of lsatis indigotica leaves （da qing ye）. Their structures including absolute configurations were determined by spectroscopic data analysis combined with comparison of their experimental CD and calculated ECD spectra. Validity of the ECD spectra calculation to assign the absolute configurations is discussed. Plausible biosynthetic pathways of 1-4 are proposed. Stereochemistry-dependent activity against LPS-induced NO production in BY2 cells was observed, and among the stereoisomers compound 4 is most active.

Ultraviolet laser photolysis of hydrocarbons for nondiamond carbon suppression in chemical vapor deposition of diamond films

In this work,we demonstrate that ultraviolet(UV)laser photolysis of hydrocarbon species alters the flame chemistry such that it promotes the diamond growth rate and film quality.Optical emission spectroscopy and laser-induced fluorescence demonstrate that direct UV laser irradiation of a diamond-forming combustion flame produces a large amount of reactive species that play critical roles in diamond growth,thereby leading to enhanced diamond growth.The diamond growth rate is more than doubled,and diamond quality is improved by 4.2%.Investigation of the diamond nucleation process suggests that the diamond nucleation time is significantly shortened and nondiamond carbon accumulation is greatly suppressed with UV laser irradiation of the combustion flame in a laser-parallel-to-substrate geometry.A narrow amorphous carbon transition zone,averaging 4 nm in thickness,is identified at the film–substrate interface area using transmission electron microscopy,confirming the suppression effect of UV laser irradiation on nondiamond carbon formation.The discovery of the advantages of UV photochemistry in diamond growth is of great significance for vastly improving the synthesis of a broad range of technically important materials.

Monitoring disulfide bonds making and breaking in biological nanopore at single molecule level

Monitoring subtle changes in ionic current flow through a nanopore could be applied to observe single molecule reaction. Here,we introduced cysteine to substitute for lysine at position 238 constructing a mutant aerolysin K238 C. It could be regarded as a nanoreactor to efficiently visualize chemical bonds making and breaking. The compound 5,5′-dithiobis-(2-nitrobenzoic acid)(DTNB) was selected as a reactant coming into collisions on the interface of the pore to occur a reversible reaction. Our results showed that the mutant aerolysin could respond to three molecules of DTNB simultaneously and reflect corresponding levels with distinguishable current signals. Therefore, this method constitutes a simple, generic tool for monitoring single molecule reaction, which evokes a guidance for the mutant aerolysin towards the application of tracking other more reactions at single molecule level.