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CONTEXT: A computational representation was used to model the doping and nanomodification of ZnO nanoparticles incorporated in Au/Fe nanocomposite. Au/Fe nanostructure was geometrically and discussed to investigate its electronic properties such electronic band structure and PDOS spectra. Moreover, the ZnO interacted with Au/Fe system was illustrated concerning the modified properties present on the surface of the nanocomposite as it may behave different attribution of band gap evaluated after ZnO modification included. Molecular dynamic simulation of the whole nano system was studied to predict the system stability concerning temperature and energy parameters during 100 ps simulation time. The most effective models under investigation were evaluated using adsorption annealing computations associated with the adsorption energy surface. A highly stable energetic adsorption system was anticipated by the periodic adsorption-annealing calculation. METHODS: Au and Fe pure metals nanostructures were studied as a separate molecule with (0 0 1) plane surface for optimum energy minimization. Dmol3 module in/materials studio software was utilized for this protocol. The designed Au/Fe layers for nanostructure building material was computationally optimized, where DFT level was considered involving generalized gradient approximation (GGA) with Perdew-Burke-Ernzerh (PBE) exchange functional. In the computations of the structure matrix simulation, the global orbital cutoff was selected. To address the weak quantification of the standard DFT functionals, Tkatchenko-Schefer (TS) (DFT + D) was utilized to precisely correct the pairwise dispersion of the functionals. The electrical parameters were interpreted using the reciprocal space of the ultrasoft pseudopotential representation. To overcome the issues of self-electron interaction, the nonlocal hybrid functional with PBE0 method was utilized to calculate the electronic properties of the studied systems. The computations generated are predicated on a particular trajectory of the gamma k-point band energy interpolations proposed in this examination. An investigation into the position of adsorption came after geometric optimization. Adsorbed on an optimized Au/Fe surface, ZnO nanostructure was computationally explored using the Dmol3 simulation software.
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CONTEXT: Electronic durable behavior on the material surface was accompanied by a class of antipsychotic drugs (APD) to describe the surface modification in the designed adsorption model. Hierarchically Zn-MOF system was utilized for estimating its capacity for drug molecule removal. Geometrically optimized strategy on the studied systems was performed using DFT/GGA/PBE. FMOs analysis was depicted based on the same level of calculations, and molecular electrostatic potential surface (MEP) was generated for unadsorbed and adsorbed systems to illustrate the variation in the surface-active sites. By interpreting the electronic density of states (DOS), the atomic orbital can be identified as a major or minor electronic distribution by PDOS graph. Adsorption locating behavior was considered to detect the significant surface interaction mode between APD and Zn-MOF surface based on lower adsorption energy. The stability of the adsorbed model was best described through dynamic simulation analysis with time through elevated temperatures. The non-covalent interactions were described using RDG/NCI analysis to show the major favorable surface interaction predicting the highly stable adsorption system. METHODS: The most accurate geometrical computations were performed using the materials studio software followed by surface cleavage and vacuum slab generation. The first principle of DFT was used to apply CASTEP module with GGA/PBE method for band structure and DOS calculations. Three systems of antipsychotic drugs were computationally studied using CASTEP simulation package and adsorbed on an optimized Zn-MOF surface. Adsorption locator module predicted the preferred adsorption mechanistic models, in which the first model was arranged to be more stable, to confirm the occurrence of some interactions in the adsorption mechanism.
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CONTEXT: Electronic sustainable behavior on the material surface and in situ metal configuration were accompted with some metal atoms like Li, Na, and K elements. Metal-doped ZrO2 crystal exported modified characteristics related to electronic conduction and exhibited some dynamic modification around the surface of the metal oxide. Computational perturbations were considered to discuss the modification behavior in addition to the studied Li, Na, and K metals. Optimization of the three doping systems was achieved followed by generating DOS and electronic band structure maps. A dynamic simulation was performed with temperature over 2000 k: the presence of the metal on the surface and prediction of its ZrO2 inclusion leading to access adsorption behavior, besides generating predictive designed models described the adsorption affinity on the solid-state surface. It cannot be neglected the importance of various metals as a main role in chemotherapy. Molecular docking investigation was considered to predict the binding behavior of the studied metal ZrO2 carrier system as an anticancer agent. Also, docking affinity was helpful in comparing the active sites binding for the studied metals, resulting in a notable binding affinity for both Li- and Na-zirconia incorporation. METHODS: The program PWSCF, which is a component of the quantum ESPRESSO suite for quantum simulation of materials, was used to construct geometric systems. The generalized gradient approximation in the Perdew-Burke-Ernzerhof (GGA/PBE) function with D3 correction (Becke-Jonson damping) was applied to the exchange-correlation energy. As the last step in the DFT postulation and design, adsorption locator annealing was carried out on the convergent models using the Materials Studio simulation package. The main roles played by metal atoms are in protein binding and the suppression of bio-active regions. For the docking process, the protein was produced using AutoDock 4.2 and Discovery Studio software in accordance with the usual methodology. Chimera and Discovery Studio were used to examine the docking data that was processed after generating specific grid box dimensions for 7BTN.
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BACKGROUND: Artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) are the currently recommended first-and second-line therapies for uncomplicated Plasmodium falciparum infections in Chad. This study assessed the efficacy of these artemisinin-based combinations, proportion of day 3 positive patients, proportions of molecular markers associated with P. falciparum resistance to anti-malarial drugs and variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). METHODS: A single-arm prospective study assessing the efficacy of AS-AQ and AL at three sites (Doba, Kelo and Koyom) was conducted between November 2020 to January 2021. Febrile children aged 6 to 59 months with confirmed uncomplicated P. falciparum infection were enrolled sequentially first to AS-AQ and then AL at each site and followed up for 28 days. The primary endpoint was PCR-adjusted adequate clinical and parasitological response (ACPR). Samples collected on day 0 were analysed for mutations in pfkelch13, pfcrt, pfmdr-1, pfdhfr, pfdhps genes and deletions in pfhrp2/pfhrp3 genes. RESULTS: By the end of 28-day follow-up, per-protocol PCR corrected ACPR of 97.8% (CI 95% 88.2-100) in Kelo and 100% in Doba and Kayoma were observed among AL treated patients. For ASAQ, 100% ACPR was found in all sites. All, but one patient, did not have parasites detected on day 3. Out of the 215 day 0 samples, 96.7% showed pfkelch13 wild type allele. Seven isolates carried nonsynonymous mutations not known to be associated artemisinin partial resistance (ART-R). Most of samples had a pfcrt wild type allele (79% to 89%). The most prevalent pfmdr-1 allele detected was the single mutant 184F (51.2%). For pfdhfr and pfdhps mutations, the quintuple mutant allele N51I/C59R/S108N + G437A/540E responsible for SP treatment failures in adults and children was not detected. Single deletion in the pfhrp2 and pfhrp3 gene were detected in 10/215 (4.7%) and 2/215 (0.9%), respectively. Dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, were observed in 5/215 (2.3%) isolates. CONCLUSION: The results of this study confirm that AS-AQ and AL treatments are highly efficacious in study areas in Chad. The absence of known pfkelch13 mutations in the study sites and the high parasite clearance rate at day 3 suggest the absence of ART-R. The absence of pfdhfr/pfdhps quintuple or sextuple (quintuple + 581G) mutant supports the continued use of SP for IPTp during pregnancy. The presence of parasites with dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, warrants the continued surveillance. Trial registration ACTRN12622001476729.
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Antimaláricos , Artemisininas , Malaria Falciparum , Adulto , Femenino , Embarazo , Humanos , Artesunato , Antimaláricos/uso terapéutico , Amodiaquina/uso terapéutico , Combinación Arteméter y Lumefantrina/uso terapéutico , Chad , Estudios Prospectivos , Arteméter , Malaria Falciparum/tratamiento farmacológico , Artemisininas/uso terapéuticoRESUMEN
We report on a novel, to the best of our knowledge, active probe for scanning near-field optical microscopy (SNOM). A fluorescent nanosphere, acting as the secondary source, is grafted in an electrostatic manner at the apex of a polymer tip integrated into the extremity of an optical fiber. Thanks to the high photostability and sensitivity of the secondary source, the near-field interaction with a gold nanocube is investigated. It is shown that the spatial resolution is well defined by the size of the fluorescent nanosphere. The polarization-dependent near-field images, which are consistent with the simulation, are ascribed to the local excitation rate enhancement. Meanwhile, measurement of the distance-dependent fluorescence lifetime of the nanosphere provides strong evidence that the local density of states is modified so that extra information on nano-emitters can be extracted during near-field scanning. This advanced active probe can thus potentially broaden the range of applications to include nanoscale thermal imaging, biochemical sensors, and the manipulation of nanoparticles.
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This paper reports on a new strategy for obtaining homogeneous dispersion of grafted quantum dots (QDs) in a photopolymer matrix and their use for the integration of single-photon sources by two-photon polymerization (TPP) with nanoscale precision. The method is based on phase transfer of QDs from organic solvents to an acrylic matrix. The detailed protocol is described, and the corresponding mechanism is investigated and revealed. The phase transfer is done by ligand exchange through the introduction of mono-2-(methacryloyloxy) ethyl succinate (MES) that replaces oleic acid (OA). Infrared (IR) measurements show the replacement of OA on the QD surface by MES after ligand exchange. This allows QDs to move from the hexane phase to the pentaerythritol triacrylate (PETA) phase. The QDs that are homogeneously dispersed in the photopolymer without any clusterization do not show any significant broadening in their photoluminescence spectra even after more than 3 years. The ability of the hybrid photopolymer to create micro- and nanostructures by two-photon polymerization is demonstrated. The homogeneity of emission from 2D and 3D microstructures is confirmed by confocal photoluminescence microscopy. The fabrication and integration of a single-photon source in a spatially controlled manner by TPP is achieved and confirmed by auto-correlation measurements.
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Local and deterministic trapping of single nanoparticles (NPs) has always been a challenging topic due to the difficulties faced at such a small particle size. These difficulties are concerned with the stability, simplicity, robustness, and efficiency of the used trapping technique. Here, we used two-photon polymerization (TPP) of a prefunctionalized photopolymer to obtain a nanometric polymer layer and selectively attract single colloidal gold NPs (AuNPs). Thanks to a deep photochemical study of the threshold energy, we identified a photopolymerization regime allowing one to tune the polymer size and immobilize single gold nanoparticles. This method is promising for the fabrication of single photon sources.
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BACKGROUND: Lesions in the ventral striatum region (above the anterior perforated substance) are a challenge for neurosurgeons due to their direct relationship with the lenticulostriate arteries, which difficult the surgical access. The standard approaches for this region include the following: 1) transfrontal approach, 2) transanterior perforating substance approach, 3) transcallosal transventricular approach, and 4) pterional transsylvian-transinsular route. In this study, we aimed to describe a novel anatomical approach through the anterior limiting sulcus of the insula in order to access the ventral striatum. METHODS: We reviewed the literature and performed a detailed dissection of this region by using Klingler's technique with brain specimens injected with silicone, paying special attention to the white fibers and lenticulostriate arteries, and provided a description of an illustrative case of a cavernous malformation. RESULTS: Neuroanatomical dissections showed that the lenticulostriate arteries had an inverted C-shaped anterior concavity, leaving less significant vascular relationships in the depth of the anterior limiting sulcus of the insula. In the case we described, the cavernous malformation was completely resected and the patient was discharged without any neurological deficits. CONCLUSIONS: The transanterior limiting sulcus of the insula approach to the ventral striatum offers a safe access route for selected cases and can be performed on the basis of anatomical references. Three-dimensional understanding of the intrinsic brain architecture and its relationships with vascular structures in this specific area is important and can be acquired mainly through laboratory training.
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Corteza Insular , Procedimientos Neuroquirúrgicos , Humanos , Procedimientos Neuroquirúrgicos/métodos , Tubérculo Olfatorio , Disección , Arteria Cerebral MediaRESUMEN
Objective: This study aimed to evaluate and compare the force degradation of two types of elastomeric chains following different periods of immersion in zinc-containing mouthwashes. Materials and Methods: Four hundred and forty pieces of Elasto-Force and Super Elasto-Force elastomeric chains were divided into two control and eight experimental groups. The pieces were stretched to 25 mm on pins mounted on an acrylic block and stored in distilled water at 37°C. The experimental groups were immersed in four different types of mouthwash for one minute twice a day throughout the test period. Ten continuous thermocycles per day between cold and hot water baths (5-55°C) were carried out. Forces were measured at six-time intervals (initial, 24 hours, 1, 3, 6, and 8 weeks). The mean force was calculated and compared among different elastomeric chains, mouthwashes, and times using the t-test and one-way ANOVA test followed by Tukey's HSD test. The level of significance was set at 0.05. Results: Both types of elastomeric chains had significant force degradation over time (74-79% at 8 weeks). The Super Elasto-Force generated a higher force level than the Elasto-Force elastomeric chain at all time points. SmartMouth Clinical DDS mouthwash had a significantly lower effect on force degradation than other mouthwashes with no significant difference compared to control groups. Conclusions: Depending on these results: there is no clinically significant difference between both types of elastomeric chains, although Super Elasto-Force delivered a higher force level. The pH of the mouthwashes could play a role in force degradation over time, rather than other ingredients including zinc. The SmartMouth mouthwash had the minimum effect on force degradation of elastomeric chains, followed by Halita, Listerine Total Care Zero, and Breath Rx, respectively.
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BACKGROUND: Cerebellar mutism (CM) is defined as the lack of speech production, despite an intact state of consciousness and cognitive function, that happens secondary to a cerebellar insult. To the best of our knowledge, only five cases have thus far been described in the English literature. In this paper, we report the sixth incidence overall, which is also the first case of a CM associated with penetrating head injury. The relevant literature is reviewed and analyzed, our current knowledge of the neuroanatomical and functional relations is summarized, and potential future research endeavors are indicated. CASE DESCRIPTION: An 8-year-old girl was transferred to our hospital having had fallen on a rod that penetrated her neck behind the ear. An urgent computed tomography scan of the head revealed a right cerebellar contusion with surrounding edema. Three days later, she became mute but was still obeying commands. Repeat imaging showed a resolving cerebellar contusion with increased edema and mass effect. By day 9, she had uttered a few words. At 1-month follow-up, the child had regained normal speech. CONCLUSION: Posttraumatic CM is a rare and probably underreported condition with only six documented cases to date. Although it may well be on the same spectrum as postoperative CM, further understanding of the exact mechanism, clinical course, and prognosis of this entity is bound to significantly improve the recovery and quality of life of head trauma patients.
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The integration of nanoparticles (NPs) into photonic devices and plasmonic sensors requires selective patterning of these NPs with fine control of their size, shape, and spatial positioning. In this article, we report on a general strategy to pattern different types of NPs. This strategy involves the functionalization of photopolymers before their patterning by two-photon laser writing to fabricate micro- and nanostructures that selectively attract colloidal NPs with suitable ligands, allowing their precise immobilization and organization even within complex 3D structures. Monolayers of NPs without aggregations are obtained and the surface density of NPs on the polymer surface can be controlled by changing either the time of immersion in the colloidal solution or the type of amine molecule chemically grafted on the polymer surface. Different types of NPs (gold, silver, polystyrene, iron oxide, colloidal quantum dots, and nanodiamonds) of different sizes are introduced showing a potential toward nanophotonic applications. To validate the great potential of our method, we successfully demonstrate the integration of quantum dots within a gold nanocube with high spatial resolution and nanometer precision. The promise of this hybrid nanosource of light (plasmonic/polymer/QDs) as optical nanoswitch is illustrated through photoluminescence measurements under polarized exciting light.
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BACKGROUND: The education and training of healthcare workers (HCWs) about pandemic response plans, infection control protocols (ICP), and precautions are critical for breaking the virus transmission chain. This study aimed to assess the knowledge of HCWs regarding the COVID-19 pandemic response plan and the ICP. Concomitantly, evaluating the effectiveness and impact of institutional measures, policies, and training programs. METHODS: A cross-sectional study using an electronic questionnaire was used to collect data from 267 HCWs at a University-affiliated-hospital during April 2020. RESULTS: In this study, 90.7% of participants were nurses and 66% were females. 60.3% of participants received specific training about caring for COVID-19 patients while at least 94.3% reviewed the pandemic response plan and ICP for COVID-19. 47.5% and 29.2% of participants provided direct care for suspected or confirmed COVID-19 patients, respectively. Between 85.7% and 100% of the participants answered all items correctly regarding the COVID-19 pandemic response plan, measures, and precautions. Furthermore, the correct answers were above 95% for each item. CONCLUSION: HCWs have a high level of knowledge about the COVID-19 pandemic response plan and ICP. Training and disseminating updated plans and protocols in different methods such as an intranet and onsite training in addition to regular methods were very effective.
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ABSTRACT: Ventilator-associated pneumonia is a life threatening device related infection in intensive care units. Methicillin-resistant Staphylococcus aureus is considered a common contagious pathogen causing pneumonia and sepsis.To assess the prevalence of S aureus in comparison to other pathogens, and their antibacterial sensitivity profile in ventilator-associated pneumonia.Data regarding ventilator-associated pneumonia of adults admitted to the intensive care unit, at the Jordan University of Science and Technology Hospital, between 2012 and 2018 were extracted from the computerized system. Microorganisms and their susceptibility profiles were identified according to the Clinical and Laboratory Standards Institute.There were 547 isolates, of which 35 (6.4%) were Gram positive, 59% were methicillin resistant. Gram-negative isolates were present in 507 (92.6%) isolates, of which 82% were multidrug resistant, and 1% were Candida species.Gram-negative bacterial infections were significantly associated with ventilation usage. S aureus was not the predominant pathogen.
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Staphylococcus aureus Resistente a Meticilina , Neumonía Asociada al Ventilador/epidemiología , Neumonía Asociada al Ventilador/microbiología , Infecciones Estafilocócicas/epidemiología , Adulto , Anciano , Cuidados Críticos , Femenino , Mortalidad Hospitalaria , Hospitales de Enseñanza , Humanos , Jordania , Tiempo de Internación , Masculino , Persona de Mediana Edad , Prevalencia , Respiración Artificial , Infecciones Estafilocócicas/diagnóstico , Centros de Atención TerciariaRESUMEN
BACKGROUND: The exact burden of varicella is not well quantified in Jordan. AIMS: This study aimed to estimate the varicella burden in paediatric patients in Jordan who sought care in a hospital-based setting. METHODS: This was a multicentre, retrospective review of medical records of patients aged 0-14 years with a primary varicella diagnosis in Jordan between 2013 and 2018. The data assessed were: use of health care resources for varicella (outpatient and inpatient visits, tests and procedures, and medication use), and clinical complications of the infection. Estimated costs were based on health care resources used (direct costs) and lost revenue to the child's caregiver (indirect costs) for outpatients and inpatients. RESULTS: In total, 140 children with varicella were included: 78 outpatients, mean age (standard deviation) 4.4 (3.2) years, and 62 inpatients, mean age 4.0 (3.8) years. No outpatients had varicella-related complications, while 32 (52%) inpatients had ≥ 1 complication. The use of health care resources was higher for inpatients than outpatients, including prescription medication use - 94% of inpatients versus 6% of outpatients. Total costs of varicella were estimated at US$ 66.1 (95% CI: 64.1-68.1) per outpatient and US$ 914.7 (95% CI: 455.6-1373.9) per inpatient. CONCLUSIONS: Varicella is associated with considerable use of health care resources in Jordan and may be responsible for annual costs of US$ 11.5 million. These results support universal varicella vaccination in Jordan.
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Varicela , Varicela/epidemiología , Varicela/terapia , Niño , Preescolar , Atención a la Salud , Hospitalización , Humanos , Jordania/epidemiología , Pacientes Ambulatorios , Estudios RetrospectivosRESUMEN
OBJECTIVES: To evaluate the impact of an antimicrobial stewardship programme (ASP) on reducing broad-spectrum antibiotic use and its effect on carbapenem-resistant Acinetobacter baumannii (CRAb) in hospitalized patients. METHODS: The study was a retrospective, ecological assessment in a tertiary teaching hospital over 6 years (January 2014 to December 2019). The intervention involved the implementation of an ASP in February 2018, which remains in effect today. This ASP consists of several components, including education, antibiotic guidelines, antibiotic restriction policy with prior approval, audit of compliance to the restriction policy and feedback. Restricted antibiotics were imipenem/cilastatin, ertapenem, meropenem, vancomycin, teicoplanin, tigecycline, colistin, amikacin, piperacillin/tazobactam, levofloxacin and ciprofloxacin. The intervention was evaluated by time-series methods. RESULTS: Statistically significant decreases in the level of antibiotic use, after the introduction of the ASP, were observed for the following antibiotics: imipenem/cilastatin (Pâ=â0.0008), all carbapenems (Pâ=â0.0001), vancomycin (Pâ=â0.0006), colistin (Pâ=â0.0016) and third-generation cephalosporins (Pâ=â0.0004). A statistically significant decrease in the slope, after the introduction of the ASP, for ertapenem (Pâ=â0.0044) and ciprofloxacin (Pâ=â0.0117) was observed. For piperacillin/tazobactam, there was a significant increasing trend (Pâ=â0.0208) before the introduction of the ASP. However, this increased trend was halted post-introduction of the ASP (Pâ=â0.4574). The introduction of the ASP was associated with a significant impact on reducing the levels of CRAb (Pâ=â0.0237). CONCLUSIONS: The introduced antimicrobial stewardship interventions contributed to a reduction in the use of several broad-spectrum antibiotics, reversed the trends of increasing use of other antibiotics and were associated with a significant reduction in CRAb.
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Acinetobacter baumannii , Programas de Optimización del Uso de los Antimicrobianos , Antibacterianos/uso terapéutico , Carbapenémicos/uso terapéutico , Hospitales , Humanos , Jordania , Pruebas de Sensibilidad Microbiana , Estudios RetrospectivosRESUMEN
Both [5]-circulene and [7]-circulene can be selected to design the molecular tweezers theoretically using the DFT method. Leaning on the cyclic polymerization mechanism, we obtain four new tweezer compounds. Theoretical results offer that tweezer compound (I) is additionally stable than other compounds because it has better energies than other compounds. The values were as follows: - 2606.83372937 a.u. for the total energy, - 5.39820 eV for (EHOMO), and 2.87407 eV for gap energy. The thermodynamic theoretical outcome showed that all reactions are exothermic and spontaneous, suggesting that tweezer compound (I) might correlate with several aromatic compounds, such as pyrene, benzo[ghi]perylene, ovalene, and hexabenzocoronene. The correlation energy results showed an increase as the aromatic compound becomes larger, while the correlation distance decreases. All correlation energy kinds are electrostatic. The value of the electrostatic correlation energy of tweezer compound (I)-ovalene is (- 6.4928615 kJ mol-1). The tweezer compound (I) has a spherical cavity equal to 3.73640 nm3, which adds an important application in the ability to capture chemicals, bacteria, or viruses that are close to the size of the cavity with ease.
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BACKGROUND: Limited information is available about COVID-19 infections among health care workers. Sensitive detection of COVID-19 cases in health care workers is crucial for hospital infection prevention policy, particularly for those who work with vulnerable patients. The aim of this study is to describe the prevalence of positive COVID-19 among asymptomatic health care workers who took care of patients with COVID-19 during the pandemic. METHODS: This retrospective study included all health care workers at King Abdullah University Hospital who take care of patients infected with COVID-19 patients from March 18, 2020 to April 29, 2020. They were tested for COVID-19 infection by use of real-time reverse-transcriptase rRT-PCR on samples from nasopharyngeal swabs. RESULTS: A total number of 370 health care workers were screened. The majority were nurses followed by physicians and other personnel. This study showed that all asymptomatic health care workers were tested negative for COVID-19Q. CONCLUSION: Unexpectedly, the prevalence of positive COVID-19 among asymptomatic health care workers who take care of patients infected with the novel coronavirus was 0%. This result must be cautiously interpreted. Further studies are needed in order to find effective strategy of screening health care workers to insure a safe working environment.
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Hybrid plasmonic nano-emitters based on the combination of quantum dot emitters (QD) and plasmonic nanoantennas open up new perspectives in the control of light. However, precise positioning of any active medium at the nanoscale constitutes a challenge. Here, we report on the optimal overlap of antenna's near-field and active medium whose spatial distribution is controlled via a plasmon-triggered 2-photon polymerization of a photosensitive formulation containing QDs. Au nanoparticles of various geometries are considered. The response of these hybrid nano-emitters is shown to be highly sensitive to the light polarization. Different light emission states are evidenced by photoluminescence measurements. These states correspond to polarization-sensitive nanoscale overlap between the exciting local field and the active medium distribution. The decrease of the QD concentration within the monomer formulation allows trapping of a single quantum dot in the vicinity of the Au particle. The latter objects show polarization-dependent switching in the single-photon regime.
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In March 2020, a wedding in Jordan led to a large outbreak of coronavirus disease (COVID-19). We collected data on 350 wedding attendees, 76 who of whom developed COVID-19. Our study shows high communicability of COVID-19 and the enormous risk for severe acute respiratory syndrome 2 virus transmission during mass gatherings.