دراسة العوامل المؤثرة في التعرف على الشاخصات المرورية في ظروف المدن السورية

عادة ًما تكون الشاخصات المرورية من أهم العوامل المؤثرة في زيادة السلامة المرورية، وتخفيف العبء الاقتصادي الناجم عن الحوادث المرورية، ويعد فهم الشاخصات أمراً مهماً للقيادة الفعالة والاستجابة للتحذيرات، بهدف إيجاد مسارات الطرق الصحيحة، وتنظيم تحركات مستخدمي الطريق، من خلال إبراز الأولويات وإعلام مستخدمي الطريق بأنظمة وظروف المرور، والشاخصات التي يتم فهمها بشكل سيء تزيد من مخاطر الحوادث وقد تعرض مستخدمي الطريق للخطر. في هذا البحث تم قياس مستوى فهم السائقين للشاخصات المرورية من خلال إجراء مسح ميداني لمجموعة من الشاخصات، لتكون دليلاً على مدى الوعي عند السائقين للتعرف على هذه الشاخصات، كما تم تقييم الوضع الراهن لها على بعض الطرق المدينية، من خلال اختيار شوارع مدينية في مدينتي اللاذقية وطرطوس، وإجراء دراسة تحليلية إحصائية للوضع الراهن للشاخصات المرورية فيها، وتحديد المعايير المؤثرة في التعرف عليها، ودراسة مدى تعرف السائقين وانتباههم إلى الشاخصات المرورية الموجودة على الطرق بشكل عام. لقد وفرت نتائج الدراسة معطيات التعديل في معايير تصميم الشاخصات المرورية، في شوارع مدينتي اللاذقية وطرطوس، مع ضرورة إعادة تأهيل الشاخصات المرورية القديمة لفهم معاني جميع الشاخصات بشكل أفضل

Consecutive single-crystal-to-single-crystal isomerization of novel octamolybdate anions within a microporous hybrid framework with robust water sorption properties

The 3D hybrid framework [{Cu(cyclam)}3(kMo8O27)]· 14H2O (1) (cyclam=1,4,8,11-tetraazacyclotetradecane) undergoes sequential single-crystal-to-singlecrystal transformations upon heating to afford two different anhydrous phases (2 a and 3a). These transitions modify the framework dimensionality and enable the isomerization of k-octamolybdate (k-Mo8) anions into λ (2 a) and μ (3 a) forms through metal migration. Hydration of 3 a involves condensation of one water molecule to the cluster to afford the γ-Mo8 isomer in 4, which dehydrates back into 3a through the 6a intermediate. In contrast, 2a reversibly hydrates to form 5, exhibiting the same Mo8 cluster as that of 1. It is remarkable that three of the Mo8 clusters (k, λ and μ) are new and that up to three different microporous phases can be isolated from 1 (2 a, 3a, and 6a). Water vapor sorption analyses show high recyclability and the highest uptake values for POM-based systems. The isotherms display an abrupt step at low humidity level desirable for humidity control devices or water harvesting in drylands.Funded by Eusko Jaurlaritza/Gobierno Vasco (EJ/GV, grants IT1722-22 and KK-2022/00045). E.R.B. thanks EJ/GV for her doctoral fellowship (PRE_2018_1_0143)

Consecutive single-crystal-to-single-crystal isomerization of novel octamolybdate anions within a microporous hybrid framework with robust water sorption properties

The 3D hybrid framework [{Cu(cyclam)}3 (κ-Mo8 O27 )] ⋅ 14H2 O (1) (cyclam=1,4,8,11-tetraazacyclotetradecane) undergoes sequential single-crystal-to-single-crystal transformations upon heating to afford two different anhydrous phases (2 a and 3 a). These transitions modify the framework dimensionality and enable the isomerization of κ-octamolybdate (κ-Mo8 ) anions into λ (2 a) and μ (3 a) forms through metal migration. Hydration of 3 a involves condensation of one water molecule to the cluster to afford the γ-Mo8 isomer in 4, which dehydrates back into 3 a through the 6 a intermediate. In contrast, 2 a reversibly hydrates to form 5, exhibiting the same Mo8 cluster as that of 1. It is remarkable that three of the Mo8 clusters (κ, λ and μ) are new and that up to three different microporous phases can be isolated from 1 (2 a, 3 a, and 6 a). Water vapor sorption analyses show high recyclability and the highest uptake values for POM-based systems. The isotherms display an abrupt step at low humidity level desirable for humidity control devices or water harvesting in drylands.Funded by Eusko Jaurlaritza/Gobierno Vasco (EJ/GV, grants IT1722-22 and KK-2022/00045). E.R.B. thanks EJ/GV for her doctoral fellowship (PRE_2018_1_0143). Technical and human support from SGIker (UPV/EHU) is gratefully acknowledged.Peer reviewe

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

The impact of solution vs. slurry vs. mechanochemical syntheses upon the sorption performance of a 2D switching coordination network

The selection and optimization of synthesis routes for porous metal–organic materials are critical for their large-scale manufacture but remain largely underexplored. In this study, we compare mechanochemistry vs. slurry vs. solution methods for the synthesis of a 1D chain coordination polymer {[Co(bpy)(NCS)2(H2O)2]·bpy}n (chn-1-Co-NCS-H2O) that is an intermediate to the 2D switching coordination network [Co(bpy)2(NCS)2]n, sql-1-Co-NCS (1 = bpy = 4,4′-bipyridine). Although neat mechanosynthesis using Co(NCS)2 and bpy as the starting materials failed, both water slurry and water-assisted mechanochemical syntheses afforded the desired intermediate, chn-1-Co-NCS-H2O, in high yield. Nevertheless, the resulting sql-1-Co-NCS products were observed to exhibit different CO2 sorption profiles depending on the synthesis methods used to prepare chn-1-Co-NCS-H2O. This study reveals that water can play an important role in mechanosynthesis, not only by inducing and accelerating the reaction process, but also by enhancing product quality in a manner that is not readily detectable by PXRD.</p

Adsorbate-dependent phase switching in the square lattice topology coordination network [Ni(4,40 -bipyridine)2(NCS)2]n

Switching coordination networks (CNs) featuring stepped sorption isotherms that are accompanied by phase changes offer promise for gas storage and separation applications. However, their responsiveness to different adsorbates remains largely understudied. Herein, we report the variable switching behaviour of a previously known square lattice (sql) topology CN, [Ni(4,4′-bipyridine)2(NCS)2] (sql-1-Ni-NCS), with respect to nine gaseous adsorbates.</p

Tuning the switching pressure in square lattice coordination networks by metal cation substitution

Coordination networks that undergo guest-induced switching between “closed” nonporous and “open” porous phases are of increasing interest as the resulting stepped sorption isotherms can offer exceptional working capacities for gas storage applications. For practical utility, the gate ad/desorption pressures (Pga/Pgd) must lie between the storage (Pst) and delivery (Pde) pressures and there must be fast switching kinetics. Herein we study the effect of metal cation substitution on the switching pressure of a family of square lattice coordination networks [M(4,4’-bipyridine)2(NCS)]n (sql-1-M-NCS, M = Fe, Co and Ni) with respect to CO2 sorption. The Clausius-Clapeyron equation was used to correlate Pga/Pgd and temperature. At 298 K, Pga/Pgd values were found to vary from 31.6/26.7 bar (M = Fe) to 26.7/20.9 bar (M = Co) and 18.5/14.6 bar (M = Ni). The switching event occurs within 10 minutes as verified by dynamic CO2 sorption tests. In addition, in situ synchrotron PXRD and molecular simulations provided structural insight into the observed switching event, which we attribute to layer expansion of sql-1-M-NCS via intercalation and inclusion of CO2 molecules. This study could pave the way for rational control over Pga/Pgd in switching adsorbent layered materials and enhance their potential utility in gas storage applications

Acetylene storage performance of [Ni(4,40-bipyridine)2(NCS)2]n, a switching square lattice coordination network†

We report that the previously reported square lattice coordination network [Ni(4,40 -bipyridine)2(NCS)2]n, sql-1-Ni-NCS, undergoes acetylene induced switching between closed (nonporous) and open (porous) phases. The resulting stepped sorption isotherms exhibit temperature controlled steps, consistent high uptake and bench-mark working capacity (185 cm 3 g 1 or 189 cm 3, 1–3.2 bar, 288 K) for acetylene storage

Dinuclear copper sulfate-based square lattice topology network with high alkyne selectivity

ABSTRACT: Porous coordination networks (PCNs) sustained by inorganic anions that serve as linker ligands can offer high selectivity toward specific gases or vapors in gas mixtures. Such inorganic anions are best exemplified by electron-rich fluorinated anions, e.g., SiF6 2−, TiF6 2−, and NbOF5 2−, although sulfate anions have recently been highlighted as inexpensive and earth-friendly alternatives. Herein, we report the use of a rare copper sulfate dimer molecular building block to generate two square lattice, sql, coordination networks which can be prepared via solvent layering or slurrying, CuSO4(1,4-bib)1.5, 1, (1,4-bib = 1,4-bisimidazole benzene) and CuSO4(1,4-bin)1.5, 2, (1,4-bin = 1,4-bisimidazole naphthalene). Variable-temperature SCXRD and PXRD experiments revealed that both sql networks underwent reversible structural transformations due to linker rotations or internetwork displacements. Gas sorption studies conducted upon the narrow-pore phase of CuSO4(1,4-bin)1.5, 2np, found a high calculated 1:99 selectivity for C2H2 over C2H4 (33.01) and CO2 (15.18), as well as strong breakthrough performance. Across-the-board, C3H4 selectivity vs C3H6, CO2, and C3H8 was also observed. Sulfate-based PCNs, although still understudied, appear increasingly likely to offer utility in gas and vapor separations.</p