可持续场地倡议(SITES)评价体系在中国城市绿地建设中的研究进展及适用性讨论

建设可持续的城市绿地是风景园林行业实现可持续发展的重要途径。然而,中国目前缺乏指导可持续景观建设的标准体系。可持续场地倡议(SITES)体系的提出和引入为国内相关研究提供了新的切入点。以SITES评价体系为研究对象,概述其起源、主要内容等,明确其在城市绿地项目建设中的应用价值,全面总结了SITES评价体系在国内研究与应用方面的进展,同时深入探讨了其在中国城市绿地建设中的适用性和局限性。SITES在关注“场地”尺度、覆盖全生命周期、设置“门槛”条件以及全球统一标准等方面展现了较强的适用性,然而,在实际应用于中国城市绿地项目时存在一定的局限性,包括SITES标准与国内标准规范的不匹配,分值权重的失衡,缺乏政府相关福利政策支持和推广受限制等问题。

Understanding Bridging Sites and Accelerating Quantum Efficiency for Photocatalytic CO_(2) Reduction

We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.

Asymmetric Zn-N_4 atomic sites embedded hollow fibers as stable Zn anode for high-performance Zn-ion hybrid capacitor

Zn based electrochemical energy storage systems(EES)have attracted tremendous interests owing to their low cost and high intrinsic safety.Nevertheless,the uncontrolled growth of Zn dendrites and the side reactions of Zn metal anodes(ZMAs)severely restrict their applications.To address these issues,we design the asymmetric Zn-N_(4) atomic sites embedded hollow fibers(AS-IHF)as the flexible host for stable ZMAs.Through introducing different nitrogen resources in the synthesis,two kinds of coordination,i,e.Zn-N(pyridinic)and Zn-N(pyrrolic),are introduced in the Zn-N_(4) atomic module synchronously.The asymmetric Zn-N_(4) module with regulated micro-environment facilitates the superior zincophilic features and promotes the Zn adsorption.Meanwhile,the highly porous structure of the hollow fiber effectively reduces local current density,homogenize Zn ion flux,and alleviate structure stress.All the advantages endow the high efficiency and good stability for Zn plating/stripping.Both theoretical and experimental results demonstrate the high reversibility,low nucleation overpotential,and dendritefree behavior of the AS-IHF@Zn anode,which afford the high stability in high-rate and long-term cycling.Moreover,the solid-state Zn-ion hybrid capacitor(ZIHC)based on AS-IHF@Zn anode shows the high flexibility,reliability,and superior long-term cycling capability in a wide-range of temperatures(-20-25℃).Therefore,the present work not only gives a new strategy for modulating local environments of single atomic sites,but also propels the development of flexible power sources for diverse electronics.

d-Orbital steered FeN_(4)moiety through N,S dual-site adjustation for zinc-air flow battery

The implementation of pristine covalent organic polymer(CO_(2)P)with well-defined structure as air electrode may spark fresh vitality to rechargeable zinc-air flow batteries(ZAFBs),but it still remains challenges in synergistically regulating their electronic states and structural porosity for the great device performance.Here,we conquer these issues by exploiting N and S co-doped graphene with COP rich in metal-ligand nitrogen to synergistically construct an effective catalyst for oxygen reduction reaction(ORR).Among them,the N and S co-doped sites with high electronegativity properties alter the number of electron occupations in the d orbital of the iron centre and form electron-transfer bridges,thereby boosting the selectivity of the ORR-catalysed four-electron pathway.Meanwhile,the introduction of COP materials aids the formation of pore interstices in the graphene lamellae,which both adequately expose the active sites and facilitate the transport of reactive substances.Benefiting from the synergistic effect,as-prepared catalyst exhibits excellent half-wave potentials(E_(1/2)=912 mV)and stability(merely 8.8%drop after a long-term durability test of 50000 s).Further,ZAFBs assembled with the N/SG@CO_(2)P catalyst demonstrate exceptional power density(163.8 mW cm^(-2))and continuous charge and discharge for approximately 140 h at 10 mA cm^(-2),outperforming the noble-metal benchmarks.

Comparison of bone artifacts from the Schöningen site in Germany and the Lingjing site in China

Similarities play an important role in the reconstruction of human physical,cultural and technological evolution.The two sites presented in this paper,the Middle Palaeolithic site Lingjing in China Layer 10 and 11 and the Lower Palaeolithic site Schöningen 13Ⅱ-4,the socalled Schöningen Spear Horizon in Germany,show striking similarities.The archaeological record of both sites includes lithic artifacts as well as a very large assemblage of fossil bones.The preservation of the material at both sites is excellent and the faunas encountered at both sites show many similarities.The faunal lists of both sites include a diverse carnivore guild,an elephant species,two different rhinoceros species,two different equids,different cervids and large bovids.Both sites also yielded bone retouchers as well as a unique record of bone hammers that show identical,unusual flaking and percussion damage.These similarities are remarkable if one takes into account the difference in age(ca 200 kaBP)and the geographical distance between the two sites of ca 8000 km.Therefore,we do not assume a close cultural link between the hominin populations active at both sites.The authors assume that the observed similarities show more or less identical,opportunistic hominin behaviour at both sites located in a comparable environment with more or less similar taphonomic conditions.

Assessing the Spatial Equality of COVID Testing Sites Maintaining Zero COVID Policy

Rapid and timely testing is essential to minimize the COVID-19 spread. Decision makers and policy planners need to determine the equal distribution and accessibility of testing sites. This study mainly examines the spatial equality of COVID-19 testing sites that maintain a zero COVID policy in Guangzhou City. The study has identified the spatial disparities of COVID testing sites, characteristics of testing locations, and accessibility. The study has obtained information on COVID testing sites in Guangzhou City and population data. Point pattern analyses, Euclidian distance and allocation, and network analyses are the main methods used to achieve the research objectives, and 1183 total COVID testing sites can be recognized in Guangzhou City. Results revealed that spatial disparities could be noticed over the study area. Testing locations of Guangzhou City are highly clustered. The most significant testing sites are located in Haizhu District, which has the third largest population. The highest population density can be identified in Yuexiu District. However, only 94 testing sites are located there. According to all the results, higher disparities can be identified, and a lack of testing sites is located in the north part of the study area. Some people in the northern part have to travel more than 10 km to reach a testing site. Finally, this paper suggests increasing the number of testing sites in the north and south parts of the study area and keeping the same distribution, considering the area, total population, and population density. This kind of research will be helpful to decision-makers in making proper decisions to maintain a zero COVID policy.

Characteristics of Gold Mineralization at the Baguiomo Gold Panning Site, Koudougou Region, Burkina Faso, West Africa

The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are located in the Kwademen-Baguiomo shear zone. This mineralization, located only a few kilometers from the Kwademen gold deposit, is uncharacterized and, together with the latter, could constitute a gold potential capable of being economically exploitable. It is in this sense that this work is carried out with a view to characterizing the gold mineralization of the Baguiomo gold panning site. To carry out this work, we have made direct field measurements, combined with microstructures, and combined all this with data from geochemical rock analysis of the basalts that are the main host formations. Geochemical data show that tholeitic basalts formed from a mantle plume that was emplaced in an oceanic plateau context. Calc-alkaline basalts and andesites are comparable to Paleoproterozoic tholeitic basalts (PTH3), which are slightly enriched in light rare earths. Fertility tests show that these basalts concentrate between 3 and 6 ppb of gold at the time of accretion, which is sufficient for remobilization of this primary gold during the Eburnian orogeny to yield a deposit of around 4 - 5 Moz. Gold mineralization is associated with pyrite crystals when the latter are disseminated in the rock mass, whereas it is associated with hematite in quartz veins concordant with S1 shear deformation. It is mainly the pyrite crystals in the pressure shadows that contain the gold grains, whose development would be synchronous with micro-shear zone reactivation during the first phase of D1B deformation. The second phase of D2B deformation, which is a crenulation or fracture schistosity, does not significantly affect the shear deformation that controls mineralization.

Ni/ZSM-5 Catalysts for Light Olefin Oligomerization:Effects of Supports and Ni Sites on Activity and Selectivity

A series of Ni/ZSM-5 containing a small amount of Ni was prepared by an ion exchanged method.The impact of the n(SiO_(2))/n(Al_(2)O_(3))ratio on the catalytic activity was studied using the samples 0.09Ni/ZSM-5(60)and 0.09Ni/ZSM-5(130).To determine the interaction between the Ni species and acid sites on the surface of the catalyst,the catalysts were characterized by N2 adsorption-desorption,X-ray diffraction(XRD),scanning electron microscopy(SEM),and UV-vis spectroscopy.The performance of the catalysts for the catalytic oligomerization of 1-hexene was investigated in detail.The nickel species were found to be uniformly distributed in all the catalysts.It was discovered that the oligomerization activity of the catalyst can be improved using Ni species;however,the contribution of Brønsted acids in oligomerization reactions is greater than that of Ni sites and Lewis acids.

An Analysis of the Fragmentation of Observing Time At the Muztagh-Ata Site

Cloud cover plays a pivotal role in assessing observational conditions for astronomical site-testing.Except for the fraction of observing time,its fragmentation also wields a significant influence on the quality of nighttime sky clarity.In this article,we introduce the functionΓ∈[0,1],designed to comprehensively capture both the fraction of available observing time and its continuity.Leveraging in situ measurement data gathered at the Muztagh-Ata site between 2017 and 2021,we showcase the effectiveness of our approach.The statistical result illustrates that the Muztagh-Ata site affords approximately 122 nights that were absolutely clear and 205 very good nights annually,corresponding toΓ≥0.9 andΓ≥0.36 respectively.

Effects of synthetic site water on bentonite-concrete system for a potential nuclear waste repository

In high-level nuclear waste(HLW)repositories,concrete and compacted bentonite are designed to be employed as buffer materials,which may raise a problem of interactions between concrete and bentonite.These interactions would lead to mineralogy transformation and buffer performance decay of bentonite under the near field environment conditions in a repository.A small-scale experimental setup was established to simulate the concrete-bentonite-site water interaction system from a potential nuclear waste repository in China.Three types of mortars were prepared to correspond to the concrete at different degradation states.The results permit the determination of the following:(1)The macroproperties of Gaomiaozi(GMZ)bentonite(e.g.swelling pressure,permeability,the final dry density,and water content of reacted samples);(2)The composition evolution of fluids from the synthetic site water-concrete-bentonite interaction systems;(3)The sample characterization including Fourier transform infrared spectroscopy(FTIR)and X-ray powder diffraction(XRD).Under the infiltration of the synthesis Beishan site water(BSW),the swelling pressure of bentonite decreases slowly with time after reaching its second swelling peak.The flux decreases with time during the infiltrations,and it tends to be stable after more than 120 d.Due to the cation exchange reactions in the BSW-concrete-bentonite systems,the divalent cations(Ca and Mg)were consumed,and the monovalent cations(Na and K)were released.The dissolution of minerals in the bentonite such as albite causes Si increasing in the pore water.It was concluded that the hydro-mechanical property degradation of bentonite takes place when it comes into contact with concrete mortar,even under low-pH groundwater conditions.The soil dispersion,the uneven water content,and the uneven dry density in bentonite samples may partly contribute to the swelling decay of bentonite.Therefore,the direct contact with concrete has an obvious effect on the performance of bentonite.

Brønsted-acid sites induced photocatalytic cracking of low-polarity polyethylene plastics

Polyolefins such as polyethylene(PE)are one of the largest-scale synthetic plastics and play a key role in modern society.However,polyethylene is extremely inert to chemical recycling owing to its lack of chemical functionality and low polarity,making it one of the most challenging environmental hazards globally.Herein,we developed a phosphorylated CeO_(2)catalyst by an organophosphate precursor and featured efficient photocatalysis of low-density polyethylene(LDPE)without the acid or alkaline pre-treatment.Compared to pristine CeO_(2),the surface phosphorylation allows to introduce Brønsted acid sites,which facilitate to form carbonium ions on LDPE via protonation.In addition,the suitable band structure of the phosphorylated CeO_(2)catalyst enables efficient photoabsorption and generates reactive oxygen species,leading to the C–C bond cleavage of LDPE.As a result,the phosphorylated CeO_(2)catalyst exhibited an outstanding carbon conversion rate of>94%after 48 h of photocatalysis under 50 mW/cm^(2)of simulated sunlight,with a high CO_(2)product selectivity of>99%.Furthermore,the PE microparticles with sizes larger than 10μm released from LDPE plastic wrap were directly and completely degraded by photocatalysis within 12 h,suggesting an attractive and environmentally benign strategy of utilizing solar energy-based photocatalysis for reducing potential hazards of LDPE plastic trashes.

Boost the Utilization of Dense FeN_(4) Sites for High-Performance Proton Exchange Membrane Fuel Cells

Iron-nitrogen-carbon(Fe-N-C)catalysts for the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs)have seriously been hindered by their poor ORR performance of Fe-N-C due to the low active site density(SD)and site utilization.Herein,we reported a melamine-assisted vapor deposition approach to overcome these hindrances.The melamine not only compensates for the loss of nitrogen caused by high-temperature pyrolysis but also effectively etches the carbon substrate,increasing the external surface area and mesoporous porosity of the carbon substrate.These can provide more useful area for subsequent vapor deposition on active sites.The prepared 0.20Mela-FeNC catalyst shows a fourfold higher SD value and site utilization than the FeNC without the treatment of melamine.As a result,0.20Mela-FeNC catalyst exhibits a high ORR activity with a half-wave potential(E_(1/2))of 0.861 V and 12-fold higher ORR mass activity than the FeNC in acidic media.As the cathode in a H_(2)-O_(2)PEMFCs,0.20Mela-FeNC catalyst demonstrates a high peak power density of 1.30 W cm^(-2),outstripping most of the reported Fe-N-C catalysts.The developed melamine-assisted vapor deposition approach for boosting the SD and utilization of Fe-N-C catalysts offers a new insight into high-performance ORR electrocatalysts.

Incidences and Risk Factors for Surgical Site Infections in Koutiala, Mali

Purpose: This paper aims to assess the incidences and risk factors for surgical site (ISO) infections in the general surgery department of the Koutiala District Hospital. Patients and Methods: This was a prospective and descriptive study from August 1, 2017 to October 31, 2020 involving all patients who underwent laparotomy in the general surgery department of the Koutiala District Hospital. Patients who were not operated on and who did not have a laparotomy were not included. Age, sex, frequency, patient history, National Nosocomial Infections Surveillance (NNIS) index, time to occur, bacteriological test results and course of infection were analyzed. Results: Fifty patients were registered. The average age was 34.2 ± 21.2 years old. Eleven patients were 60 years old or older. The hospital incidence rate was 4.3% and the community incidence rate was 6.1 cases per 100,000 population. The concept of smoking was noted in 15 patients. Patients were operated on in emergency 84% of cases. Peritonitis was the most common initial lesion with 32% of cases. Our patients had an NNIS index greater than 0 in 84% of cases. The time to develop infection from the surgical site was less than 3 days in 8 patients (16% of cases). Depending on the depth of the infection, it was superficial (cutaneous) in 39 patients (78%) and deep (subcutaneous and organic) in 11 patients (22%). Escherichia coli was the most common germ with 72% followed by staphylococcus aureus at 24%. We noted 22% morbidity. The median length of hospitalization was 9 ± 2.2 days. Conclusion: ISO is common in our service. Prevention and mastery require knowledge of risk factors.

PVDF-assisted pyrolysis strategy for corrugated plate oxygen electrocatalysis nanoreactor:Simultaneously realizing efficient active sites and rapid mass transfer

Though Zn-air batteries(ZABs)are one of the most promising system for energy storage and conversion,challenge still persists in its commercial application due to the sluggish kinetics of oxygen reduction/evolution reaction(ORR/OER).Hereby,a polyvinylidene fluoride(PVDF)-assisted pyrolysis strategy is proposed to develop a novel corrugated plate-like bifunctional electrocatalyst using two-dimensional zeolitic imidazolate frameworks(2D ZIF-67)as the precursor.The employed PVDF plays an important role in inheriting the original 2D structure of ZIF-67 and modulating the composition of the final products.As a result,a corrugated plate-like electrocatalyst,high-density Co nanoparticles decorated 2D Co,N,and F tri-doped carbon nanosheets,can be obtained.The acquired electrocatalyst enables efficient active sites and rapid mass transfer simultaneously,thus showing appreciable electrocatalytic performance for rechargeable Zn-air batteries.Undoubtedly,our proposed strategy offers a new perspective to the design of advanced oxygen electrocatalysts.

Quantitative Analysis of Seeing with Height and Time at Muztagh-Ata Site Based on ERA5 Database

Seeing is an important index to evaluate the quality of an astronomical site.To estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanalysis database(ERA5)is used.Seeing calculated from ERA5 is compared consistently with the Differential Image Motion Monitor seeing at the height of 12 m.Results show that seeing decays exponentially with height at the Muztagh-Ata site.Seeing decays the fastest in fall in 2021 and most slowly with height in summer.The seeing condition is better in fall than in summer.The median value of seeing at 12 m is 0.89 arcsec,the maximum value is1.21 arcsec in August and the minimum is 0.66 arcsec in October.The median value of seeing at 12 m is 0.72arcsec in the nighttime and 1.08 arcsec in the daytime.Seeing is a combination of annual and about biannual variations with the same phase as temperature and wind speed indicating that seeing variation with time is influenced by temperature and wind speed.The Richardson number Ri is used to analyze the atmospheric stability and the variations of seeing are consistent with Ri between layers.These quantitative results can provide an important reference for a telescopic observation strategy.

The suitability assessment on site selection for bottom seeding scallop culture based on analytic hierarchy process

Scallop culture is an important way of bottom-seeding marine ranching,which is of great significance to improve the current situation of fishery resources.However,there are some problems in site-selection evaluation of marine ranching,such as imperfect criteria system,complex structure,untargeted criteria quantification,etc.In addition,no site-selection evaluation method of bottom-seeding culture areas for scallops is available.Therefore,we established a hierarchy structure model according to the analytic hierarchy process(AHP)theory,in which social,physical,chemical,and biological environments are used as main criteria,and marine functional zonation,water depth,current,water temperature,salinity,substrate type,water quality,sediment quality,red tide,phytoplankton,and zooplankton are used as sub-criteria,on which a multi-parameter evaluation system is set up.Meanwhile,the dualism method,assignment method,and membership function method were used to quantify sub-criteria,and a quantitative evaluation for the entire criteria was added,including the evaluation and analysis of two types of unsuitable environmental situations.By overall consideration in scallop yield,quality,and marine ranching construction objectives,the weight of the main criteria could be determined.Five grades in the suitability corresponding to the evaluation result were divided,and the Python language was used to create an evaluation system for efficient calculation and intuitive presentation of the evaluation outcome.Eight marine cases were simulated based on existing survey data,and the results prove that the method is feasible for evaluating and analyzing the site selection of bottom-seeding culture areas for scallops under various environmental situations.The proposed evaluation method can be promoted for the site selection of bottom-seeding marine ranching.This study provided theoretical and methodological references for the site selection evaluation of other types of marine ranching.

Surgical Site Infections in Trauma and Orthopaedics at Bouaké Teaching Hospital (Côte d’Ivoire)

Background: Surgical site infections are serious healthcare problems. The aim was to describe the epidemiological, diagnostic, therapeutic, and prognostic aspects of surgical site infections in Trauma and Orthopaedics at Bouaké Teaching Hospital. Method: This retrospective, descriptive, and analytical study was conducted from January 2019 to December 31, 2021. The data studied included prevalence, initial lesions, type of surgical intervention, type of SSI, bacteria involved, treatment, and outcomes. Results: Forty-four (11%) of the 399 patients included in the study developed a surgical site infection. The mean age was 27 years, with 36 male and 8 female. Initial lesions were predominantly open fractures (n = 31;70%), with a mean delay of 48 hours for surgical management. Emergency interventions accounted for 70% (n = 31) of cases. The NNISS infection risk score was 1 in 80% (n = 35) of cases. Superficial infections (n = 34;77%) appeared early, on a mean 6 days postoperatively. Bacteriological analysis primarily identified Pseudomonas aeruginosa (n = 10;23%), sensitive to Imipenem and Chloramphenicol but resistant to Amoxicillin-clavulanic acid, Ceftriaxone, Gentamicin, and Ciprofloxacin. Multidrug-resistant bacteria were found in 89% (n = 8) of cases, with all bacteria resistant to Ceftriaxone. Surgical revision was performed in 10 patients (23%), primarily involving debridement with hardware retention (n = 7;70%). Chloramphenicol was the most commonly used antibiotic post-antibiogram (61%). Outcomes were favourable in 98% of cases. Identified risk factors included the type of lesion according to NRC classification, the delay in managing open fractures, and the NNISS score. Conclusion: The prevalence of surgical site infection was 11%, favoured by the delayed operation of open fractures.

Pd^(0)-O v-Ce^(3+) Interfacial Sites with Charge Redistribution for Enhanced Hydrogenation of Methyl Oleate to Methyl Stearate

Improving the efficiency of metal/reducible metal oxide interfacial sites for hydrogenation reactions of unsaturated groups(e.g.,C=C and C=O)is a promising yet challenging endeavor.In our study,we developed a Pd/CeO_(2) catalyst by enhancing the oxygen vacancy(O V)concentration in CeO_(2) through high-temperature treatment.This process led to the formation of an interface structure ideal for supporting the hydrogenation of methyl oleate to methyl stearate.Specifi cally,metal Pd^(0) atoms bonded to the O V in defective CeO_(2) formed Pd^(0)-O v-Ce^(3+)interfacial sites,enabling strong electron transfer from CeO_(2) to Pd.The interfacial sites exhibit a synergistic adsorption eff ect on the reaction substrate.Pd^(0) sites promote the adsorption and activation of C=C bonds,while O V preferably adsorbs C=O bonds,mitigating competition with C=C bonds for Pd^(0) adsorption sites.This synergy ensures rapid C=C bond activation and accelerates the attack of active H*species on the semi-hydrogenated intermediate.As a result,our Pd/CeO_(2)-500 catalyst,enriched with Pd^(0)-O v-Ce^(3+)interfacial sites,dem-onstrated excellent hydrogenation activity at just 30℃.The catalyst achieved a Cis-C18:1 conversion rate of 99.8% and a methyl stearate formation rate of 5.7 mol/(h·g metal).This work revealed the interfacial sites for enhanced hydrogenation reactions and provided ideas for designing highly active hydrogenation catalysts.

Efficient and reversible separation of NH_(3) by deep eutectic solvents with multiple active sites and low viscosities

The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.

Surgical site infection following pancreaticoduodenectomy in a referral cancer center in Mexico

Background: Pancreaticoduodenectomy is the standard treatment for resectable periampullary cancer. Surgical site infections(SSI) are common complications with increased morbidity. The study aimed to describe the prevalence, risk factors, microbiology, and outcomes of SSI among patients undergoing pancreaticoduodenectomy. Methods: We conducted a retrospective study in a referral cancer center between January 2015 and June 2021. We analyzed baseline patient characteristics and SSI occurrence. Culture results and susceptibility patterns were described. Multivariate logistic regression was used to determine risk factors, proportional hazards model to evaluate mortality, and Kaplan-Meier analysis to assess long-term survival. Results: A total of 219 patients were enrolled in the study;101(46%) developed SSI. Independent factors for SSI were diabetes mellitus, preoperative albumin level, biliary drainage, biliary prostheses, and clinically relevant postoperative pancreatic fistula. The main pathogens were Enterobacteria and Enterococci. Multidrug-resistance rate in SSI was high but not associated with increased mortality. Infected patients had higher odds of sepsis, longer hospital stay and intensive care unit stay, and readmission rate. Neither 30-day mortality nor long-term survival was significantly different between infected and non-infected patients. Conclusions: SSI prevalence among patients undergoing pancreaticoduodenectomy was high and largely caused by resistant microorganisms. Most risk factors were related to preoperative instrumentation of the biliary tree. SSI was associated with greater risk of unfavorable outcomes;however, survival was unaffected.