A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury

Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

A"messenger zone hypothesis"based on the visual three-dimensional spatial distribution of motoneurons innervating deep limb muscles

Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneuro ns.Howeve r,current research on the spatial location of the spinal motoneurons innervating differe nt muscles is limited.In this study,we investigated the spatial distribution and relative position of different motoneurons that control the deep muscles of the mouse hindlimbs,which were innervated by the obturator nerve,femoral nerve,inferior gluteal nerve,deep pe roneal nerve,and tibial nerve.Locations were visualized by combining a multiplex retrograde tracking technique compatible with three-dimensional imaging of solvent-cleared o rgans(3DISCO)and 3-D imaging technology based on lightsheet fluorescence microscopy(LSFM).Additionally,we propose the hypothesis that"messenger zones"exist as interlaced areas between the motoneuron pools that dominate the synergistic or antagonist muscle groups.We hypothesize that these interlaced neurons may participate in muscle coordination as messenger neurons.Analysis revealed the precise mutual positional relationships among the many motoneurons that innervate different deep muscles of the mouse.Not only do these findings update and supplement our knowledge regarding the overall spatial layout of spinal motoneurons that control mouse limb muscles,but they also provide insights into the mechanisms through which muscle activity is coordinated and the architecture of motor circuits.

Internal limiting membrane peeling combined with silicone oil or air tamponade for highly myopic foveoschisis

AIM:To compare the efficacy of pars plana vitrectomy(PPV)combined with internal limiting membrane(ILM)and silicone oil or sterile air tamponade for the treatment of myopic foveoschisis(MF)in highly myopic eyes.METHODS:This retrospective study included 48 myopic eyes of 40 patients with MF and axial lengths(ALs)ranging from 26-32 mm treated between January 2020 and January 2022.All patients were underwent PPV combined with ILM peeling followed by sterile air or silicone oil tamponade and followed up at least 12mo.Based on the features on spectral-domain optical coherence tomography(SD-OCT),the eyes were divided into the MF-only group(Group A,n=15 eyes),MF with central foveal detachment group(Group B,n=20 eyes),and MF with lamellar macular hole group(Group C,n=13 eyes).According to AL,eyes were further divided into three groups:Group D(26.01-28.00 mm,n=12 eyes),Group E(28.01-30.00 mm,n=26 eyes),and Group F(30.01-32.00 mm,n=10 eyes).The best-corrected visual acuity(BCVA),central foveal thickness(CFT),and complications were recorded.RESULTS:The patients included 16 males and 24 females with the mean age of 56±9.82y.The BCVA and CFT improved in all groups after surgery(P<0.01),while there was no significant difference of the CFT in Group A,B,and C postoperatively(P>0.05).The intergroup differences of BCVA and CFT postoperatively were statistically significant in Group D,E,and F.Twenty eyes were injected with sterile air,and 28 eyes were injected with silicone oil for tamponade based on the AL.However,there was no statistically significant difference among Groups D,E,and F in terms of the results of sterile air or silicone oil tamponade.The mean recovery time was 5.9mo for MF patients subjected to silicone oil tamponade and 7.7mo for patients subjected to sterile air tamponade,and the difference was not statistically significant.CONCLUSION:PPV and ILM peeling combined with silicone oil or sterile air tamponade can achieve good results for MF in highly myopic eyes with ALs≤32 mm.

High H_(2) selective performance of Ni-Fe-Ca/H-Al catalysts for steam reforming of biomass and plastic

The development of a selective catalyst for the conversion of biomass and plastics into H2by steam reforming can combat the energy crisis and global warming.In this work,support Ni-Fe-Ca/H-Al bifunctional catalysts were prepared by loading Ni and Fe into pretreatment CaO/Al_(2)O_(3)(Ca/H-Al)carriers and showed high catalytic activity for the steam reforming of biomass and plastic.Moreover,the idea of bidirectional degradation was exploited to strengthen the pyrolysis of plastic with a high H/C and biomass with a high O/C.Interestingly,the products presented high H2selective(1302.10 m L/g)and low CO_(2)yield(120.23 m L/g)in 7Ni-5Fe-Ca/H-Al(2:4)catalyst compared with current reports.Here,the abundant oxygen vacancies(Ov)in the H-Al carrier exhibited an electron-deficient nature,providing active sites for anchoring Ni O.Meanwhile,Ni O interacted with Ca_(2)Fe_(2)O_(5)to produce more defective Ovsites,which stabilized the NiO particles in the 7Ni-5Fe-Ca/H-Al(2:4)catalyst,and the interaction between the catalyst and the carrier was enhanced,leading to the reduction of weakly basic sites,this property promoted the strong adsorption of CO_(2)and H2O by the catalyst,contributing to the enhancement of efficient steam conversion and the promotion of conversion of by-products to H2.Notably,7Ni-5Fe-Ca/H-Al(2:4)catalysts maintained structural integrity after regeneration and exhibited excellent regenerability in H2selection and CO_(2)adsorption.The work provides a new idea for the study of efficient H2production from steam reforming of biomass and plastics.

Sepsis-induced immunosuppression:mechanisms,diagnosis and current treatment options

Sepsis is a common complication of combat injuries and trauma,and is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection.It is also one of the significant causes of death and increased health care costs in modern intensive care units.The use of antibiotics,fluid resuscitation,and organ support therapy have limited prognostic impact in patients with sepsis.Although its pathophysiology remains elusive,immunosuppression is now recognized as one of the major causes of septic death.Sepsis-induced immunosuppression is resulted from disruption of immune homeostasis.It is characterized by the release of antiinflammatory cytokines,abnormal death of immune effector cells,hyperproliferation of immune suppressor cells,and expression of immune checkpoints.By targeting immunosuppression,especially with immune checkpoint inhibitors,preclinical studies have demonstrated the reversal of immunocyte dysfunctions and established host resistance.Here,we comprehensively discuss recent findings on the mechanisms,regulation and biomarkers of sepsis-induced immunosuppression and highlight their implications for developing effective strategies to treat patients with septic shock.

Combination of cataract surgery with intravitreal injection of dexamethasone intravitreal implant(Ozurdex)for uveitis-induced cataract

AIM:To evaluate the long-term results of patients with chronic uveitis-induced cataract by phacoemulsification with IOL implantation and intravitreal injection of dexamethasone(DEX)intravitreal implant(Ozurdex).METHODS:The study included 32 eyes of 26 patients treated with DEX implant due to chronic uveitis-induced cataract and followed up for at least a year.Best-corrected visual acuity(BCVA),intraocular pressure(IOP),anterior chamber reaction,central macular thickness(CMT),intraoperative and postoperative complications and uveitis recurrence were analyzed retrospectively.RESULTS:A successful surgery was performed in all patients.The average follow-up period was 12mo.The female/male ratio was 13/13.Mean age was 45.65±3.83y(range 26 to 65y).Etiologically,rheumatic arthritis occurred in 6 patients(18.75%),ankylosing spondylitis in 4(12.50%),HLA-B27 associated uveitis in 3(9.38%),Vogt-KoyanagiHarada-associated uveitis in 4(12.50%),Behcet’s disease in 2(6.25%),and 7(21.88%)suffered from unknown diseases.All 32 eyes had varying degrees of improvement at 12mo after surgery,with 2 eyes showing BCVA of 0.1 or below(6.25%),6 having 0.1-0.5(18.75%),18 of 0.5-1.0(56.25%),and 6 of 1.0 or above(18.75%).No cases with increased IOP were observed.The values of mean CMT was increased at day 1,decreased at 1,3mo after surgery and increased at 6,12mo after surgery.No severe uveitis reactions,such as fibrinous exudates in the anterior chamber and exudative membrane formation on the anterior surface of the IOL,were observed after surgery.CONCLUSION:The present studies show that intravitreal injection of Ozudex during cataract operation can provide a new option for the clinical treatment of uveitis-induced cataract.

视网膜内界膜平铺覆盖与内界膜剥除治疗巨大型黄斑裂孔疗效的比较

目的:探讨玻璃体切除(par plana vitrectomy,PPV)+视网膜内界膜(inner limiting membrane,ILM)平铺覆盖+玻璃体腔消毒空气填充术与PPV+ILM剥除+玻璃体腔消毒空气填充术治疗巨大型特发性黄斑裂孔(idiopathic macularhole,IMH)和高度近视黄斑裂孔(macular hole,MH)的疗效差异。方法:选取巨大型IMH 40眼,巨大型高度近视性MH 40眼的临床资料进行临床对照研究。20眼巨大型IMH患者行传统ILM剥除(A1组),余20眼行ILM平铺覆盖(A2组); 20眼巨大型高度近视性MH行传统ILM剥除(B1组),余20眼行ILM平铺覆盖(B2组)。术后随诊6mo以上,对比分析MH的闭合率、手术前后最佳矫正视力(best corrected visual acuity,BCVA)改善情况。结果:A组患者手术前后BCVA改善情况差异有统计学意义(F时间=96. 193,P时间<0. 01,F组间=4. 971,P组间=0. 03,F交互=18. 772,P交互<0. 01);对不同时间点进行两两比较,结果显示:术前和术后1、3、6mo之间,术后1mo与3、6mo,术后3mo与术后6mo之间差异均有统计学意义(P<0. 05),比较不同时间两组之间的t检验结果显示,A1和A2在术前视力差异无统计学意义(P> 0. 05),术后1、3、6mo差异均有统计学意义(P <0. 05)。B组患者手术前后BCVA改善情况差异有统计学意义(F时间=136. 150,P时间<0. 01,F组间=5. 179,P组间=0. 029,F交互=7. 079,P交互=0. 001);对不同时间点进行两两比较,结果显示:术前和术后1、3、6mo之间,术后1mo与3、6mo,术后3mo与术后6mo之间差异均有统计学意义(P <0. 05),比较不同时间两组之间的t检验结果显示,B1和B2在术前视力差异无统计学意义(P>0. 05),术后1、3、6mo差异均有统计学意义(P<0. 05)。随访6mo,A1组裂孔闭合16眼(80%),4眼(20%)贴附,A2组裂孔闭合20眼(100%); B1组裂孔闭合14眼(70%),6眼(30%)贴附,B2组中裂孔闭合18眼(90%),2眼(10%)贴附。A1组和A2组组间在黄斑裂孔闭合率上差异无统计学意义(P=0. 053),B1组和B2组组间在黄斑裂孔闭合率上差异无统计学意义(P=0. 118),视网膜内界膜剥除组裂孔闭合30眼(75%),10眼(25%)贴附和平铺覆盖组黄斑裂孔闭合38眼(95%),2眼(5%)贴附,差异有统计学意义(χ2=4. 057,P<0. 05)。结论:对于巨大型IMH和巨大型高度近视MH患者,ILM平铺覆盖治疗组在闭合率及BCVA提高上明显优于ILM剥除组。

质谱快速鉴定血培养阳性标本的方法研究

目的建立快速、精准的细菌质谱鉴定方法,以缩短血培养阳性的实验周转时间。方法共收集血培养阳性瓶91个(活性炭吸附瓶),采集培养液分别转种肉汤和血平板增菌培养4 h后,用基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)进行菌种鉴定。以血平板培养24 h的质谱鉴定结果为对照,比较2种方法细菌质谱鉴定符合率。结果 91株细菌包括51株革兰阴性菌和40株革兰阳性菌。4 h肉汤增菌法和4 h血平板培养法鉴定到种的符合率分别为46.15%和89.01%,无鉴定结果率分别为47.25%和3.30%,错误鉴定率分别为3.30%和4.40%。2种方法鉴定到种的符合率比较,差异有统计学意义(P <0.05),4 h血平板培养法鉴定到种的符合率高于4 h肉汤增菌法。2种方法对革兰阴性菌鉴定到种的符合率分别为58.82%和94.12%,差异有统计学意义(P <0.05),4 h血平板培养法高于4 h肉汤增菌法。2种方法对革兰阳性菌鉴定到种的符合率分别为30.00%和82.50%,差异有统计学意义(P <0.05),4 h血平板培养法高于4 h肉汤增菌法。结论 4 h血平板培养质谱鉴定法可快速鉴定血培养阳性标本中的病原菌。

Application of acoustic radiation force impulse imaging for the evaluation of focal liver lesion elasticity

BACKGROUND: Acoustic radiation force impulse (ARFI) imaging is a new elastography method for the evaluation of tissue stiffness. This study aims to evaluate the performance of ARFI in noninvasive assessment of the tissue stiffness of focal liver lesion (FLL) and to explore its potential value in the differential diagnosis of FLL. METHODS: ARFI was performed in 140 patients with 154 FLLs, which included 28 hemangiomas (ANGIs), 14 focal nodular hyperplasias (FNHs), 61 hepatocellular carcinomas (HCCs), 39 metastases and 12 cholangiocellular carcinomas (CCCs). Virtual touch tissue quantification (VTTQ) values were obtained, analyzed and compared. The area under the receiver operating characteristic curve (AUROC) and optimal cut-off values were obtained using a receiver operating characteristic (ROC) curve analysis to assess diagnostic performance. All cases were definitively diagnosed using histopathology, CT, MRI or contrast-enhanced ultrasound. RESULTS: The VTTQ median values of ANGI, FNH, HCC metastasis and CCC were 1.30, 1.80, 2.52, 3.08 and 3.89 m/s respectively. A significant increase in the VTTQ values of different lesions was observed: ANGI【FNH【HCC【metastasis 【CCC (P【0.001). The AUROC (95% CI) of VTTQ values was 0.94 (0.90-0.98) for ANGI, 0.91 (0.87-0.96) for malignant lesions and 0.87 (0.79-0.94) for CCC. The sensitivity and specificity for ANGI (86.5%, 89.3%, respectively), malignancy (81.3% 92.9%, respectively), and CCC (91.7%, 72.5%, respectively) were associated with VTTQ cut-off values of 1.76, 2.22 and 3.00 m/s respectively.CONCLUSIONS: ARFI can accurately and objectively assess the elasticity of lesions by obtaining the shear wave elastic value of FLL with VTTQ. Therefore, ARFI is a novel, simple, noninvasive and useful diagnostic method for the characterization of FLL.

Clinical outcomes with large macular holes using the tiled transplantation internal limiting membrane pedicle flap technique

AIM: To report the surgical technique and efficacy of the tiled transplantation internal limiting membrane(ILM) pedicle flap technique after vitrectomy for 33 patients with large macular hole(MH). METHODS: This study was a prospective noncontrolled interventional study. All patients were treated by vitrectomy, the tiled transplantation ILM pedicle flap and gas tamponade. All patients underwent visual acuity measurements and optical coherence tomography(OCT), during preoperative and the follow-up visits postoperative. RESULTS: Two high-myopic patient had flap dislocation during surgery. The thorough closure of MH following the tiled transplantation ILM pedicle flap technique was ultimately achieved in 31 patients observed by OCT imaging(93.94%) 1 wk after surgery. Visual acuity improved from 1.51±0.31(logMAR) preoperative to 0.92±0.30 6 mo after surgery(P=0.000). There were no significant changes in OCT finding during the follow-up period from 1 mo to 6 mo after surgery. CONCLUSION: The tiled transplantation ILM pedicle flap technique provides bridge for retinal gliosis to achieve successful closures of the large MHs, and the microenvironment of this technique is more similar to the normal physiological conditions.

Effects of delayed repair of peripheral nerve injury on the spatial distribution of motor endplates in target muscle

Motor endplates(MEPs) are important sites of information exchange between motor neurons and skeletal muscle, and are distributed in an organized pattern of lamellae in the muscle. Delayed repair of peripheral nerve injury typically results in unsatisfactory functional recovery because of MEP degeneration. In this study, the mouse tibial nerve was transected and repaired with a biodegradable chitin conduit, immediately following or 1 or 3 months after the injury. Fluorescent α-bungarotoxin was injected to label MEPs. Tissue optical clearing combined with light-sheet microscopy revealed that MEPs were distributed in an organized pattern of lamellae in skeletal muscle after delayed repair for 1 and 3 months. However, the total number of MEPs, the number of MEPs per lamellar cluster, and the maturation of single MEPs in gastrocnemius muscle gradually decreased with increasing denervation time. These findings suggest that delayed repair can restore the spatial distribution of MEPs, but it has an adverse effect on the homogeneity of MEPs in the lamellar clusters and the total number of MEPs in the target muscle. The study procedures were approved by the Animal Ethics Committee of the Peking University People's Hospital(approval No. 2019 PHC015) on April 8, 2019.

Evaluation of the long-term effect of foldable capsular vitreous bodies in severe ocular rupture

AIM:To evaluate the long-term effect of foldable capsular vitreous body(FCVB)in the treatment of severe ocular rupture to provide a practical basis for clinical selection.METHODS:A total of 26 patients(26 eyes),23 men and 3 women,with severe ocular rupture who underwent FCVB implantation between March 2018 and September 2018 were retrospectively analysed.All open ocular wounds located in zone III,with preoperative visual acuity grade IV and above(Snellen less than 4/200).The best corrected visual acuity(BCVA),intraocular pressure(IOP),cornea,anterior chamber,iris,lens,choroid,and retina were evaluated before and after the surgery.The subjective feeling and the location of FCVB were also assessed.RESULTS:The average age of the 26 patients was 36y(20-60y).Postoperative follow-up was from 10 to 14mo.At the end of follow up,BCVA was light perception(LP)in 10 cases,no light perception(NLP)in 13 cases,hand motions(HM)in 3 cases.IOP was 11±5 mm Hg.Corneal degeneration was in 3 cases and corneal endothelial dystrophy was in 7 cases.Shallow anterior chamber was in 8 cases and hyphema was in 8 cases.Organized membrane in the pupil was in 14 cases.Epiphora occurred in 3 cases.FCVB drainage tube exposed in 3 cases.All FCVBs were in their normal location and no rejection occurred.CONCLUSION:FCVB implantation is a long-term effective treatment and may provide a practical selection for severe ocular rupture.

Synthesis of dihydrocapsaicin and dihydrocapsiate exclusively from lignocellulosic platform chemicals

Biorefinery is pivotal to the sustainability of modern chemical industry.However,since biomass is oxygen-enriched,new and green chemical strategies are required for expanding the biomass derived chemical space.In this work,synthesis of natural products dihydrocapsaicin and dihydrocapsiate was achieved exclusively from lignocellulosic platform chemicals.Natural products dihydrocapsaicin and dihydrocapsiate were synthesized exclusively from lignocellulosic platform chemicals,using furfural(from hemicellulose)and methyl isopropyl ketone(from cellulose)through aldol condensation-hydrolysis-hydrodeoxygenation to synthesize 8-methylnonanoic acid and then combined with vanillin derivates(from lignin).This synthesis demonstrates the feasibility of constructing natural products entirely from renewable biomass platform through green processes.The utilization of inherent functional groups of biomass demonstrates their potential to open up chemical space.

The loess microstructure kinds and its seismic subsidence

The paper put forward a new method of loess microstructure analysis to determine whether the loess seismic subsidence deformation to be strong or weak. In the dryer and colder climatic conditions of northwest of China, the loess microstructure formed in certain conditions changed by the special climate and desert surroundings. According to its chemical element ratio (such as Si/Al, Ca/Fe, K/Al, Ca/Mg) and seismic subsidence, we could divide them into four kinds of microstructures: strong shear deformation microstructure(I);strong compaction deformation microstructure(II);the medium seismic subsidence microstructure(III);the low seismic subsidence microstructure(IV). It could generally judge and set deeply defense measures to seismic engineering.

A GROUND STATE SOLUTION TO THE CHERN-SIMONS-SCHRODINGER SYSTEM

In this paper,we consider the Chern-Simons-Schrodinger system{−Δu+[e^(2)|A|^(2)+(V(x)+2eA_(0))+2(1+κq/2)N]u+q|u|^(p−2)u=0,−ΔN+κ^(2)q^(2)N+q(1+κq2)u^(2)=0,κ(∂_(1)A_(2)−∂_(2)A_(1))=−eu^(2),∂_(1)A_(1)+∂_(2)A_(2)=0,κ∂_(1)A_(0)=e^(2)A_(2)u^(2),κ∂_(2)A_(0)=−e^(2)A_(1)u^(2),where u∈H^(1)(R^(2)),p∈(2,4),Aα:R^(2)→R are the components of the gauge potential(α=0,1,2),N:R^(2)→R is a neutral scalar field,V(x)is a potential function,the parametersκ,q>0 represent the Chern-Simons coupling constant and the Maxwell coupling constant,respectively,and e>0 is the coupling constant.In this paper,the truncation function is used to deal with a neutral scalar field and a gauge field in the Chern-Simons-Schrödinger problem.The ground state solution of the problem(P)is obtained by using the variational method.

Sub-Tenon's urokinase injection-assisted vitrectomy in early treatment of suprachoroidal hemorrhage: Four cases report

BACKGROUND Suprachoroidal hemorrhage(SCH) is a rare but potentially catastrophic ocular event. Surgery for SCH is often challenging because of the difficulty in resolving the retinal and choroidal detachment. Here, we describe a novel surgical technique in which urokinase is administered by sub-Tenon's injection to target an organized clot in SCH prior to drainage.CASE SUMMARY A consecutive case series of four eyes with serous and hemorrhagic choroidal detachments secondary to cataract surgery or trauma was documented to evaluate the feasibility of using a sub-Tenon's urokinase injection-assisted 23-gauge and 20-gauge incision to drain choroidal detachments. Urokinase(2000 IU) was given by sub-Tenon's injection one day before surgery for clot liquefaction. A 23-gauge infusion line was placed in the anterior chamber. A 20-gauge incision was created in the suprachoroidal space 3.5 mm from the limbus. After drainage, pars plana vitrectomy was performed because of concomitant pathology that demanded this additional procedure. Visual acuity, ocular findings, the timing of surgical interventions, surgical procedures, and outcomes were retrospectively reviewed in four patients. Postoperative follow-up of the patients ranged from 6 to 24 mo(mean, 13 mo). After the treatment, all patients achieved excellent anatomical recovery. CONCLUSION Sub-Tenon's urokinase injection-assisted vitrectomy makes clot liquefaction happen in the early treatment stage, resulting in marked stability during the procedure.

Nano polystyrene microplastics could accumulate in Nile tilapia(Oreochromis niloticus):Negatively impacts on the intestinal and liver health through water exposure

Microplastics(MPs)have become a significant concern for their potential toxicity.However,the correlation between the size of plastic particles and their toxicity remains inconclusive.Here,we investigate the toxic effects of different sizes(80 nm,800 nm,8μm and 80μm)polystyrene MPs(PS-MPs)on the model organism Nile tilapia(Oreochromis niloticus).The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body.H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm group.Ed U labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm group.The gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm group.The analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm group.In conclusion,this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver toxicity.All the above lay the foundation for further study on the pathological damage of MPs to other organisms.

Catalytic conversion of mixed polyolefins under mild atmospheric pressure

The chemical recycling of polyolefin presents a considerable challenge,especially as upcycling methods struggle with the reality that plastic wastes typically consist of mixtures of polyethylene(PE),polystyrene(PS),and polypropylene(PP).We report a catalytic aerobic oxidative approach for polyolefins upcycling with the corresponding carboxylic acids as the product.This method encompasses three key innovations.First,it operates under atmospheric pressure and mild conditions,using O_(2) or air as the oxidant.Second,it is compatible with high-density polyethylene,low-density polyethylene,PS,PP,and their blends.Third,it uses an economical and recoverable metal catalyst.It has been demonstrated that this approach can efficiently degrade mixed wastes of plastic bags,bottles,masks,and foam boxes.

Pangolin HKU4-related coronaviruses found in greater bamboo bats from southern China

Coronavirus(CoV)spillover originating from game animals,particularly pangolins,is currently a significant concern.Meanwhile,vigilance is urgently needed for coronaviruses carried by bats,which are known as natural reservoirs of many coronaviruses.In this study,we collected 729 anal swabs of 20 different bat species from nine locations in Yunnan and Guangdong provinces,southern China,in 2016 and 2017,and described the molecular characteristics and genetic diversity of alphacoronaviruses(αCoVs)and betacoronaviruses(βCoVs)found in these bats.Using RT-PCR,we identified 58(8.0%)bat CoVs in nine bat species from six locations.Furthermore,using the Illumina platform,we obtained two representative full-length genomes of the bat CoVs,namely TyRo-CoV-162275 and TyRo-CoV-162269.Sequence analysis showed that TyRo-CoV-162275 shared the highest identity with Malayan pangolin(Manis javanica)HKU4-related coronaviruses(MjHKU4r-CoVs)from Guangxi Province,whereas TyRo-CoV-162269 was closely related to HKU33-CoV discovered in a greater bamboo bat(Tylonycteris robustula)from Guizhou Province.Notably,TyRo-CoV-162275 has a putative furin protease cleavage site in its S protein and is likely to utilize human dipeptidyl peptidase-4(hDPP4)as a cell-entry receptor,similar to MERSCoV.To the best of our knowledge,this is the first report of a bat HKU4r-CoV strain containing a furin protease cleavage site.These findings expand our understanding of coronavirus geographic and host distributions.

Multi-objective optimization strategy for distribution network considering V2Genabled electric vehicles in building integrated energy system

Based on the large-scale penetration of electric vehicles(EV)into the building cluster,a multi-objective optimal strategy considering the coordinated dispatch of EV is proposed,for improving the safe and economical operation problems of distribution network.The system power loss and node voltage excursion can be effectively reduced,by taking measures of time-of-use(TOU)price mechanism bonded with the reactive compensation of energy storage devices.Firstly,the coordinate charging/discharging load model for EV has been established,to obtain a narrowed gap between load peak and valley.Next,a multi-objective optimization model of the distribution grid is also defined,and the active power loss and node voltage fluctuation are chosen to be the objective function.For improving the efficiency of optimization process,an advanced genetic algorithm associated with elite preservation policy is used.Finally,reactive compensation capacity supplied by capacitor banks is dynamically determined according to the varying building loads.The proposed strategy is demonstrated on the IEEE 33-node test case,and the simulation results show that the power supply pressure can be obviously relieved by introducing the coordinated charging/discharging behavior of EV;in the meantime,via reasonable planning of the compensation capacitor,the remarkably lower active power loss and voltage excursion can be realized,ensuring the safe and economical operation of the distribution system.