50 research outputs found

    Light but strong

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    The journey of a single polymer chain to a nanopore

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    Single chain translocation has been eagerly studied for more than two decades due to its importance in biological processes and also, providing a better understanding of polymer dynamics. Polymer translocation can be divided into three stages of reaching the pore, entering the pore and passing through it. We study the delivery of the chain from the bulk to the entrance, which is called the capture process, for a single chain driven by hydrodynamic flow. Our molecular dynamics-lattice Boltzmann simulations show that the converging flow around the nanopore not only facilitates the process of finding the pore but also deforms the chain in a way that the insertion happens mostly by one of the ends. We explain why single-file capture happens most often despite the formation of folded shapes or hairpins

    Undetected leprosy in an endemic area: A case report

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    Leprosy is an infectious disease causing irreversible disability if unnoticed. A 69-year-old man with undetected leprosy from 30 years ago referred to us with claw hand and Madrosis (Milphosis). The patient complained of non-healing and painless ulcers on the extremities as well as numbness in the right leg. He told the medical team that he could not feel his feet in his shoes. The patient had blurred vision and lacrimation two weeks before admission. He had a history of recurrent foot ulcers from 25 years ago although he referred to medical staff about 5 years ago with infected wound on the hands and multiple scars of pervious ulcers. The disabilities were mainly in consequence of late visit to healthcare centers, misdiagnosis, difficult access to medical centers and patient's unawareness. The case showed the significance of medical education and public awareness for signs and symptoms of leprosy to be recognized and treated on time. In conclusion detecting leprosy should not be delayed just because of a decrease in the number of cases especially in an endemic area like Kurdistan, Iran

    Kikuchi-Fujimoto disease in a young female with discoid lupus and alopecia

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    Kikuchi-Fujimoto disease is an uncommon, benign, autoimmune condition characterized by lymphadenopathy, fever, and neutropenia. It is a self-contained condition of unidentified etiology. A 38-year-old female of Iranian Kurdish origin referred to us with multiple neck swellings, fever, and generalized arthropathy. There was no weight loss and no history of tuberculosis, medication intake, or allergy. Clinical examination revealed bilateral large, mobile, and tendercervical lymphadenopathy. Cardiovascular, respiratory, and neurological examination was normal. The patient had leucopenia and thrombocytopenia. Kikuchi-Fujimoto disease must be considered in the differential diagnosis of a female patient with fever and cervical lymphadenopathy

    Numerical Simulation of Frost Formation on a Plate-Fin Evaporator

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    In the present paper, the Eulerian-granular model is adopted, to predict the frost growth on one channel of a plate-fin evaporator. A proper mass transfer model and modified frosting criteria are used to simulate the frost formation process. First, the model is validated with experimental data obtained under various operating conditions. The numerical predictions for the frost thickness and density are in good agreement with available experimental data. Furthermore, a parametric analysis is carried out to study the impact of the geometrical parameters of a three-dimensional plate-fin evaporator. A qualitative comparison shows a good agreement between the numerical data and experimental observations reported in the literature. One interesting outcome emerging from this study is that the distance between refrigerant tubes can play an important role in the frosting time

    Investigation on the Performance of a Compact Three-Fluid Combined Membrane Contactor for Dehumidification in Electric Vehicles

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    In this paper, the performance of a compact Three-Fluid Combined Membrane Contactor (3F-CMC) is investigated using Computational Fluid Dynamics (CFD), supported and validated with a good agreement by an experimental campaign made on a fully working prototype. This internally-cooled membrane contactor is the core component of a hybrid air conditioning system for electric vehicles (EVs) developed in a successful H2020 project called XERIC. In the adopted numerical approach, the conjugate heat and mass transfer inside the 3F-CMC is described by non-isothermal incompressible flows and vapor transport through a PTFE hydrophobic membrane. The sensitivity of the 3F-CMC performance to air/desiccant flow rates, temperature, humidity, and desiccant concentration is analyzed numerically through the validated CFD codes. According to this study, the moisture removal increases by the inlet humidity ratio, nearly linearly. Under the considered conditions (where the inlet air temperature is 26.2C), when the inlet relative humidity (RH) is 75% the moisture removal is about 450% higher than the case RH = 37%, while the absorption effectiveness declines about 45%. Furthermore, this study shows that the amount of absorbed vapor flux rises by increasing the airflow rate; on the other hand, the higher the airflow rate, the lower is the overall absorption efficiency of the 3F-CMC. This investigation gives important suggestions on how to properly operate a 3F-CMC in order to achieve the requested performance, especially in hot and humid climates

    3D-CFD analysis of the effect of cooling via minitubes on the performance of a three-fluid combined membrane contactor

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    Abstract A 3D computational fluid dynamics model was adopted to study the effects of internal cooling on the performance of a three-fluid combined membrane contactor (3F-CMC), in the presence of minitubes in solution and a spacer in the air channel. This compact 3F-CMC is part of a hybrid climate-control system, recently developed for serving in electric vehicles. For the studied operating conditions, results show that the absorption and sensible effectiveness parameters increase up to 77% and 124% by internal cooling, respectively. This study also reports 3D flow effects on the heat and mass transfer enhancement inside the contactor, with implications for further design improvements

    Evaluation of the status of antibiotic prescription in patients admitted to a teaching hospital in west of Iran

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    BACKGROUND: The aim of this study was to evaluate the status of the appropriate use of antibiotics by type, dosage, and length of treatment and the route of administration in Tohid teaching hospital, Sanandaj, Iran.METHODS: In a retrospective descriptive study, 400 patients were systematically selected from patients receiving antibiotics hospitalized in Tohid hospital from March 2016 to March 2017. Demographic characteristics, hospitalization ward, diagnosis, antibiotic prescribed, dosage, length of treatment, the route of administration, and prescribing physician were recorded. The treatments were compared with standard treatment based on Harrison reference. The data were analyzed using STATA software.RESULTS: Out of total patients, 54% were men and 46% were women with a mean age of 57.87 ± 9.87 years. The mean duration of hospitalization was 6.37 ± 2.69 days. More and less numbers of patients were admitted in the internal medicine ward (23.75%) and intensive care unit (ICU) (1.00%), respectively, The highest antibiotics were administered by internal medicine specialists (40.25%), the most commonly prescribed antibiotic was ceftriaxone (34.59%), and the most common cause of antibiotic therapy was pneumonia (20.50%). Out of 595 antibiotics prescribed, 28.50% of the administrations were inappropriate. In addition, the objective for the prescription of the first and second antibiotic was inappropriate in 27.50% and 33.70% of cases, respectively. Dosage, route of administration, and the length of treatment of the prescribed antibiotic was inappropriate in 9.00%, 0.50%, and 41.00% of cases, respectively. The highest and lowest rate of inappropriate antibiotic prescription was observed in surgical (51.31%) and infectious diseases (12.90%) wards.CONCLUSION: Due to the increase inappropriate administration of antibiotics, it is necessary to train the specialists about the planning, appropriate medical consultations for antibiotic therapy, and limitation of the new antibiotics prescription.

    Evaluation of the status of antibiotic prescription in patients admitted to a teaching hospital in west of Iran

    Get PDF
    BACKGROUND: The aim of this study was to evaluate the status of the appropriate use of antibiotics by type, dosage, and length of treatment and the route of administration in Tohid teaching hospital, Sanandaj, Iran. METHODS: In a retrospective descriptive study, 400 patients were systematically selected from patients receiving antibiotics hospitalized in Tohid hospital from March 2016 to March 2017. Demographic characteristics, hospitalization ward, diagnosis, antibiotic prescribed, dosage, length of treatment, the route of administration, and prescribing physician were recorded. The treatments were compared with standard treatment based on Harrison reference. The data were analyzed using STATA software. RESULTS: Out of total patients, 54% were men and 46% were women with a mean age of 57.87 ± 9.87 years. The mean duration of hospitalization was 6.37 ± 2.69 days. More and less numbers of patients were admitted in the internal medicine ward (23.75%) and intensive care unit (ICU) (1.00%), respectively, The highest antibiotics were administered by internal medicine specialists (40.25%), the most commonly prescribed antibiotic was ceftriaxone (34.59%), and the most common cause of antibiotic therapy was pneumonia (20.50%). Out of 595 antibiotics prescribed, 28.50% of the administrations were inappropriate. In addition, the objective for the prescription of the first and second antibiotic was inappropriate in 27.50% and 33.70% of cases, respectively. Dosage, route of administration, and the length of treatment of the prescribed antibiotic was inappropriate in 9.00%, 0.50%, and 41.00% of cases, respectively. The highest and lowest rate of inappropriate antibiotic prescription was observed in surgical (51.31%) and infectious diseases (12.90%) wards. CONCLUSION: Due to the increase inappropriate administration of antibiotics, it is necessary to train the specialists about the planning, appropriate medical consultations for antibiotic therapy, and limitation of the new antibiotics prescription

    Pancytopenia as a rare complication of acute Brucellosis: A case report

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    Human Brucellosis still challenges many physicians, especially in developing countries where it is still a very common, but sometimes ignored disease. Its reemergence in developed countries and its status as a class B bioterrorist agent has recently attracted much interest. Having over 500,000 new cases annually, Brucellosis is known as one of the most common zoonotic infections in the world and “the great imitator” because of many clinical and hematological manifestations. Brucellosis is still endemic in many developing countries and remains under-diagnosed and sometimes missed reported. Although this province (Kurdistan, Iran) is a Brucella endemic area with a very high prevalence and incidence rate, except for very few and negligible case reports, we did not find any reports or epidemiological study regarding this zoonotic infection. This is the first reported case of Brucellosis with pancytopenia from this western province of Iran which has been neglected. Our case was a 16-year-old girl referred with protracted fever during the last month and undetermined diagnosis. She also suffered from generalized pain, pale skin, sweating, anorexia, and weight loss. After clinical surveying, taking history, and physical examination, Brucella infection was suspected. Diagnosis confirmed by standard tube agglutination test (STA), 1/640. The patient was successfully treated with doxycycline, rifampicin, and ceftriaxone
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