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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

The Characteristics of Eosinophilc Lung Diseases Cause by Toxocara Canis Larval Infestation (개회충 유충 감염에서 발생되는 호산구성 폐질환의 특성)

  • Kim, Yu Jin;Kyung, Sun Young;An, Chang Hyeok;Lim, Young Hee;Park, Jung Woong;Jeong, Seong Hwan;Lee, Sang Pyo;Choi, Dong Chull;Jeong, Young Bae;Kang, Shin Yong
    • Tuberculosis and Respiratory Diseases
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    • v.62 no.1
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    • pp.19-26
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    • 2007
  • Background: Toxocariasis is a common cause of eosinophilia and eosinophilic lung disease in Korea. We analyzed the characteristics of eosinophilic lung disease in toxocariasis. Method: One hundred and forty one patients with eosinophilia caused by a toxocara larval infection were evaluated from September 1, 2001 through March 30, 2006. The plain chest x-ray, chest CT(computed tomography), and bronchoalveolar larvage(BAL) were examined. A diagnosis of toxocariasis was made by ELISA using that secretory-excretory antigen from the T. canis larvae. Results: Toxocarial eosinophilic lung diseases was diagnosed in 32 out of 141 patients. Ground glass attenuation was the main feature on the CT scans in 23 out of 141 patients (71.9%). Thirteen patients (40.6%) had a random in zonal distribution on CT. Pleural effusion was observed in 9 patients (28.1%). Twenty eight patients (87.5%) complained of respiratory symptoms. Eleven patients (34.4%) had gastrointestinal symptoms and 12 patients (37.5%) had liver infiltration. Conclusions: The most common findings of the chest CT in patients with toxocariasis was a randomly distributed ground grass attenuation. A toxocara infection should be considered in a differential diagnosis of patients who exhibit pulmonary infiltration with eosinophilia in Korea.

Reinforcing Effects around Face of Soil-Tunnel by Crown & Face-Reinforcing - Large Scale Model Testing (천단 및 막장면 수평보강에 의한 토사터널 보강효과 - 실대형실험)

  • Kwon Oh-Yeob;Choi Yong-Ki;Woo Sang-Baik;Shin Jong-Ho
    • Journal of the Korean Geotechnical Society
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    • v.22 no.6
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    • pp.71-82
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    • 2006
  • One of the most popular pre-reinforcement methods of tunnel heading in cohesionless soils would be the fore-polling of grouted pipes, known as RPUM (reinforced protective umbrella method) or UAM (umbrella arch method). This technique allows safe excavation even in poor ground conditions by creating longitudinal arch parallel to the tunnel axis as the tunnel advances. Some previous studies on the reinforcing effects have been performed using numerical methods and/or laboratory-based small scale model tests. The complexity of boundary conditions imposes difficulties in representing the tunnelling procedure in laboratory tests and theoretical approaches. Full-scale study to identify reinforcing effects of the tunnel heading has rarely been carried out so far. In this study, a large scale model testing for a tunnel in granular soils was performed. Reinforcing patterns considered are four cases, Non-Reinforced, Crown-Reinforced, Crown & Face-Reinforced, and Face-Reinforced. The behavior of ground and pipes as reinforcing member were fully measured as the surcharge pressure applied. The influences of reinforcing pattern, pipe length, and face reinforcement were investigated in terms of stress and displacement. It is revealed that only the Face-Reinforced has decreased sufficiently both vertical settlement in tunnel heading and horizontal displacement on the face. Vertical stresses along the tunnel axis were concentrated in tunnel heading from the test results, so the heading should be reinforced before tunnel advancing. Most of maximum axial forces and bending moments for Crown-reinforced were measured at 0.75D from the face. Also it should be recommended that the minimum length of the pipe is more than l.0D for crown reinforcement.

Epidemic acute interstitial pneumonia in children occurred during the early 2006s (2006년 초에 유행한 소아 급성 간질성폐렴)

  • Cheon, Chong Kun;Jin, Hyun-Seung;Kang, Eun Kyeong;Kim, Hyo Bin;Kim, Byoung-Joo;Yu, Jinho;Park, Seong Jong;Hong, Soo-Jong;Park, June Dong
    • Clinical and Experimental Pediatrics
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    • v.51 no.4
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    • pp.383-390
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    • 2008
  • Purpose : This study was aimed to analyze the clinical characteristics of patients with acute interstitial pneumonia who had presented similar clinical patterns from March to June, 2006 and to describe our experience of treatment and to identify risk factors associated with prognosis. Methods : The clinical characteristics, radiologic and histopathologic findings and response to steroids of 15 patients (non-survival group [n=7] and survival group [control, n=8]) with acute interstitial pneumonia were investigated through the review of medical records. Results : The mean age of the patients was 26 (range: 3-48) months. Cough, cyanosis and fever were frequent symptoms. The most frequent radiologic findings on admission were pneumomediastium and extensive ground glass opacity. Surgical lung biopsy was performed on 8/15 (53.3%) patients and diffuse alveolar damage was found. Mechanical ventilation was applied for 9/15 (60.0%) patients for 40 (range: 1-99) days. Five patients in survival group received steroid treatment and 7 patients in non-survivial group (P=0.20). One patient in survival group received steroid pulse treatment and 4 patients in non-survival group (P=0.12). Seven patients died all of respiratory failure. The survival rate was 53.4%. Conclusion : The patients with acute interstitial pneumonia which occurred on spring 2006 showed high mortality because of rapidly and extensively progressing pulmonary fibrosis and air leakage. Therefore, we should consider surgical lung biopsy and steroid application earlier. We should recognize this acute interstitial pneumonia occurring on spring in domestics and need to investigate the cause and treatment in large scale.

Clinical Features of Dermatomyositis/Polymyositis(DM/PM) with Lung Involvement (폐를 침범한 피부근염/다발성근염의 임상적 양상)

  • Park, Gun-Min;Choi, Chang-Min;Um, Sang-Won;Hwang, Yong-Il;Yim, Jae-Joon;Lee, Jae-Ho;Yoo, Chul-Gyu;Lee, Choon-Taek;Chung, Hee-Soon;Song, Young-Wook;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.51 no.4
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    • pp.354-363
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    • 2001
  • Background : Although lung involvement has been reported in 5 to 46% of dermatomyositis/polymyositis(DM/PM) patients, reports of the condition in Korea are rare. This study evaluated the clinical features of lung involvement in DM/PM patients. Methods : The medical records, laboratory results and radiologic findings of 79 DM/pM patients, who attended the Seoul National University Hospital (SNUH) between 1989 and 1999, were reviewed retrospectively. Results : A total 79 patients of whom 24 patients(33%) showed lung involvement, were enrolled in this study. More patients with lung involvement were female(F:M=11:1), and older compared with those without lung involvement. Patients with lung involvement presented with dyspnea(79%), coughing(67%), an elevated ESR, and CK/LD. Anti-Jo 1 antibody test was positive in 30%, which is significantly higher in patients with lung involvement. A simple chest X-ray of the patients with lung involvement exhibited reticular opacity(50%), reticulonodular opacity(30%), patchy opacity(29%), nodular opacity(13%) and linear opacity(4%). HRCT(n=24) showed ground glass opacity(75%), linear or septal thickening(50%), patchy consolidation(42%), honey-combing(33%) and nodular opacity(17%). The pulmonary function test showed a restrictive ventilatory pattern(77%) and a lower diffusing capacity(62%). The patients were followed up during a mean duration of $30{\pm}28$ months. They were treated with steroid only(50%) or a combination of steroids and cytotoxic agents(46%). Muscle symptoms were improved in 89% with treatment, but an improvement in the respiratory symptoms or in the pulmonary function test was rare. Patients with lung involvement had a higher mortality rate(21%) than those without lung involvement(10%) during the follow-up periods. Conclusion : DM/PM patients with lung involvement were mostly female, older and had a higher positive rate Anti-Jo 1 antibodies, but there was no significant difference in prognosis.

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Cystic Fibrous Dysplasia in the Kong Bone (낭종성 섬유성 이형성증)

  • Bahk, Won-Jong;Rhee, Seung-Koo;Kang, Yong-Koo;Lee, An-Hi;Park, Jeong-Mi;Chung, Yang-Guk;Choi, Kwang-Cheon
    • The Journal of the Korean bone and joint tumor society
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    • v.13 no.1
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    • pp.22-30
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    • 2007
  • Purpose: We describe clinical, radiographic, MRI and pathologic findings as well as final outcome after simple curettage and bone graft of cystic fibrous dysplasia (FD) in the long bone, which has been rarely documented in the literature. Materials and Methods: Clinical records, radiographs, MRI and histologic slides of 11 patients with cystic FD in the long bone were retrospectively analyzed. Results: Six patients complained pain for several months, 4 patients presented pain after trivial injury event, and 1 patient suffered pathologic fracture. The mode of involvement was monostotic in 10 patients and polyostotic in l patient. The femur was affected in 7 patients, the humerus in 3, and the radius in 1. Radiography showed prominent, expansive lysis associated with ground-glass density of FD. MRI revealed 2 different signals of FD and cyst. Microscopic examination revealed classic findings of FD and non-specific cystic degeneration. The final outcome was satisfactory in every patient. Local recurrence was not observed. Conclusion: Cystic FD in the long bone seems not as rare as the scarcity of reported cases would indicate. MRI features provide a basis for differential diagnosis between benign cystic change and malignant transformation. Cystic FD would be an indication for surgery and simple curettage with allo-chip-bone graft is effective.

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Two Cases of Hot Tub Lung in Bodyscrubbers Working in a Public Bath (대중목욕탕 근무 후 발생한 온수 욕조 폐 2예)

  • Bak, Ji Young;Kim, Kwang Sil;Park, I-Nae;Yum, Ho-Kee;Lee, Seung Heon;Lee, Hyun-Kyung;Lee, Young Min;Jung, Hoon;Hur, Jin-Won;Lee, Seong Soon;Lee, Hyuk Pyo;Choi, Soo Jeon;Shin, Eun Ah;Choi, Sang Bong
    • Tuberculosis and Respiratory Diseases
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    • v.66 no.1
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    • pp.37-41
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    • 2009
  • Hot tub lung has been described as a pulmonary illness associated with exposure to nontuberculous mycobacteria,mainly hot bathtub water contaminated with Mycobacterium avium complex (MAC) and hence the name. Although not entirely clear, its etiology has been thought to involve either an infection or a hypersensitivity pneumonitis secondary to MAC. Herein, we describe 2 female patients (60 and 53 years old) admitted to our hospital with hot tub lung, and both of whom worked in a public bath. Both women were initially admitted following several months of exertional dyspnea and cough. The patients had been working as body-scrubbers in a public bath for several years. Their chest CT scans showed bilateral diffuse ground-glass opacities with multifocal air-trappings and poorly defined centrilobular nodules in both lungs. Pathological findings from lung specimens revealed small non-necrotizing granuloma in the lung parenchyme with relatively normal-looking adjacent alveoli. Discontinuation of working in the public bath led to an improvement in symptoms and radiographic abnormalities, without antimycobacterial therapy.

Differences in CT Findings According to Sputum Smear Results in Patients with Active Pulmonary Tuberculosis Having a Single Cavity (한 개의 공동이 있는 활동성폐결핵 환자에서 객담도말검사 결과에 따른 흉부CT 소견의 차이)

  • Song, In Sup;Lee, Hwa Yeun;Yoo, Seung Min
    • Tuberculosis and Respiratory Diseases
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    • v.62 no.6
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    • pp.479-485
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    • 2007
  • Background: The purpose of this study was to evaluate the differences in CT findings according to sputum smear-positive or -negative results in patients with active pulmonary tuberculosis having a single cavity. Methods: A total of 32 patients with active pulmonary tuberculosis having a single cavity on CT were classified into two groups: smear-positive (n=19) and smear-negative (n=13). The CT findings were reviewed retrospectively. The presence of consolidation, the number of lobes showing consolidation, ground-glass opacity, micronodules and nodule, the maximum diameter of the cavity, and the shape and maximum thickness of the cavity wall were assessed. Result: The maximum diameter of the cavity was $33.84{\pm}13.65mm$ and $27.08{\pm}9.04mm $ in the smear-positive and -negative groups, respectively (p>0.05). The amount of consolidation and the number of lobes with consolidation were found to be 89.5% and 30.8% (p=0.01) and $1.37{\pm}0.90$ and $0.31{\pm}0.48$ (p=0.0002) in the smear-positive and -negative groups, respectively. Consolidations in two or more lobes were only noted in 31.6% of in the sputum smear- positive group (p< 0.05). There were no other significant differences between the two groups. The sensitivity, specificity, positive and negative predictive values for the presence of consolidation were 89.5%, 69.2%, 73.9%, and 81.8%, respectively. Conclusion: While the absence of consolidation on CT may be associated with sputum smear-negative results in patients with active pulmonary tuberculosis having a single cavity, the presence of consolidation in two or more lobes on CT may be associated with spear-positive results in these patients.

The Correlation of TUNEL Apoptotic Index with Clinicoradiologicopathologic Scores in Interstitial Lung Disease (간질성 폐질환에서 TUNEL 아포프토시스 지수와 임상적, 방사선학적, 및 병리학적 지표와의 상관관계)

  • Kim, Youn-Seup;Myung, Na-Hye;Park, Jae-Seuk;Jee, Young-Koo;Lee, Kye-Young
    • Tuberculosis and Respiratory Diseases
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    • v.53 no.2
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    • pp.136-147
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    • 2002
  • Background : Interstitial lung disease has various manifestations that are differentiated by their pathology, progress and treatment. However, all manifestations eventually progresses to pulmonary fibrosis. Recent studies have shown that apoptosis of pulmonary epithelial cells might be related to pulmonary fibrosis. The correlation of the apoptotic index with the clinical manifestations, pathological findings, HRCT findings and the response to treatment were examined. Materials and Methods : Twenty subjects (14 men, 16 women), who had been diagnosed with interstitial lung disease through an open lung biopsy, were enrolled in this study. The subtypes were one AIP, two NIP, eight BOOP, and seven UIP cases. The apoptotic index was scaled from 0-2 depending on the fraction of positive staining cells by TUNEL method. The clinical severity was assessed by a modification of a previously developed CRP scoring system. The pathologic scores were based on 4 components: fibrosis, cellularity, desquamation, and granulation. In the HRCT study, each lobe was scored by the radiologists on a scale for both fibrosis and ground-glass attenuation. The treatment response was assessed by an increase in more than 10% of the CRP score, and comparing the results 3 months before and after treatment. Results : The apoptotic index showed no correlation with the CRP and HRCT scoring system. The apoptotic index correlated with the pathologic elements including fibrosis, cellularity and the desquamation score (p<0.05). Of the 16 patients who received corticosteroid therapy, 9 patients (56.3%) responded to therapy. There was no correlation between the response to corticosteroid and the apoptotic index. In the case of patients with acute and subacute ILD, the apoptotic index showed a correlation with the cellularity, desquamation, and the total histological score (p<0.05). In the case of patients with chronic ILD, the apoptotic index correlated with the fibrosis and cellularity score (p<0.05). Conclusion : Apoptosis of the pulmonary epithelial cells is implicated in the pathogenesis of interstitial lung disease particularly on a pathological basis.

The Diagnosis of Pneumoniae Following Bone Marrow Transplantation by Bronchoscopy (골수이식후 기관지내시경을 이용한 폐렴의 진단)

  • Kim, Tae-Yon;Yoon, Hyeong-Kyu;Moon, Hwa-Sik;Park, Sung-Hak;Min, Chang-Ki;Kim, Chun-Choo;Jung, Jung-Im;Song, Jeong-Sup
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.2
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    • pp.198-206
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    • 2000
  • Background : Pulmonary complications following bonemarrow transplantation (BMT) are common and associated with a high mortality rate. We investigated the yield, safety, and impact of fiberoptic bronchoscopy (FOB) for diagnosis of postBMT pneumoniae. Methods : From May 1997 to April 2000, 56 FOBs were performed in 52 post BMT patients for clinical pneumoniae. BMT patients with respiratory symptoms and/or pulmonary infiltrates had a thoracic HRCT(high resolution computed tomography) and bronchoscopic examination including BAL (bronchoalveolar lavage), TBLB (transbronchial lung biopsy), PSB (protected specimen brush). Results : The characteristics of the subjects were as follows : 37 males, 15 females, mean age of 31.3 years(l7-45), 35 sibling donor allogenic BMTs, 15 nonrelated donor allogenic BMTs, and 2 autologous BMTs. Fiftynine percent of FOBs (33 FOBs, 31 patients) were diagnostic. Isolated pathogens included the following : 12 cytomegalovirus (CMV) (21.4 %), 7 pneumocystis carinii (PC) (12.5 %), 11 CMV with PC (19.6 %), 2 Mycobacaterium tuberculosis (3.6%), and 1 streptococcus (1.8%). Most of the radiographic findings were diffuse interstitial lesions. CMV pneumoniae had mainly diffuse interstitial nodular lesion, and PC pneumoniae had diffuse, interstitial ground glass opacity(GGO). When CMV was accompanied by PC, a combined pattern of nodular and GGO was present. Of the 56 cases (23.2%), 13 died of CMV pneumoniae (n=2), PCP (n=2),mixed infection with CMV and PC (n=3), underlying GVHD (n=1), underlying leukemia progression (n=1), or respiratory failure of unknown origin (n=4). There was no major complication by bronchoscopy. Only 3 cases developed minor bleeding and 1 episode temporary hypoxemia. Conclusion : Based on our findings, CMV and PC are the major causes of postBMT pneumoniae. In addition, BAL can be considered a safe and accurate procedure for the evaluation of pulmonary complications after BMT.

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