Search

Bin-Bin Jin, Yan Ma, Xiu-Hua Zhao, Yi-Ling Teng, Shang-Yong Zhu Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of ChinaCorrespondence: Shang-Yong Zhu, Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, Guangxi, 530021, People’s Republic of China, Email zhushangyong@sina.comObjective: To analyze the risk factors of the operators on contrast agent intravasation during hysterosalpingo-contrast sonography (HyCoSy).Methods: We retrospectively collected 399 infertile women who underwent HyCoSy by the same sonographer. These patients were divided into two groups according to the way how the assistants connected the syringe to the uterus radiography catheter to inject the contrast agent. We analyzed whether the use of different contrast bolus injection methods had any influence on the incidence of intravasation during HyCoSy.Results: There was no significant difference between the two groups with different cross-sectional areas of the syringe outflow tract in the risk variables for intravasation, but the intravasation rates of the two groups were different, 26.4% in group A and 17.1% in group B, P < 0.05. The primary manifestation was that when both fallopian tubes were unobstructed, the intravasation rate of group B with smaller cross-sectional area of the outflow tract of the syringe was lower, and the difference was statistically significant. The inferences drawn from our physics model were also in line with the clinical results.Conclusion: The influence of different operators on the contrast agent intravasation rate of HyCoSy cannot be ignored. The assistants of HyCoSy examination should inject the contrast agent slowly and steady, and a needle can be used as a flow restrictor to control the flow into the uterine cavity per unit time, slow down the rising speed of intrauterine pressure, and avoid the accumulation of contrast agent in the uterine cavity, so as to reduce the intravasation caused by operator factors.Keywords: intravasation, hysterosalpingo-contrast sonography, ultrasonography, contrast agent, fallopian tube patency, infertility

Bin-Bin Jin,1,* Yi-Zhen Gong,2,* Yan Ma,1 Zhong-Hui He3 1Department of Ultrasonography, 2Department of Evidence-Based Medicine, 3Department of Gynecology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People’s Republic of China *These authors contributed equally to this work Background: Ultrasonography, the preferred adjunct examination method and the differential diagnostic tool for gynecologic emergency, can reflect the change pattern of gynecological diseases in daytime and at night. The purpose of this study was to analyze the diseases through gynecological emergency ultrasound in daytime and at night and to evaluate the day–night difference in the accuracy of ultrasound diagnosis.Materials and methods: Retrospective analysis was performed on the 2016 clinical data of the patients who had undergone gynecological emergency ultrasound at The First Affiliated Hospital of Guangxi Medical University, and the results of the ultrasound diagnosis were compared with the clinical diagnosis.Results: The following categories of gynecologic emergency diseases during the daytime and at night have significant statistical differences in the constituent ratio (P0.05). The overall coincidence rate of ultrasound diagnosis was 96.3% (daytime, 97.9%; night, 86.4%). The coincidence rates of ectopic pregnancy ultrasonography diagnosis in daytime and at night were 96.4 and 75.4%, respectively; the difference was statistically significant (P

Background and Objective: Hepatic injury after cardiac surgery is considered to be a consequence of cardiopulmonary bypass (CPB). The aim of this study was to test the hypothesis that penehyclidine hydrochloride (PHC) could attenuate hepatic injury using a rat CPB model.Methods: Male Sprague-Dawley rats were randomly divided into six groups (eight per group), including sham-operated control, sham low-dose PHC control (0.6 mg kg), sham high-dose PHC control (2.0 mg kg), vehicle control, low-dose PHC (0.6 mg kg) and high-dose PHC (2.0 mg kg)-treated groups. Blood samples were collected from the femoral artery at the cessation of CPB and the serum levels of the liver enzymes, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were determined. The ultrastructure of liver tissue was also examined under an electron microscope.Results: In the sham-operated groups, high-dose PHC and low-dose PHC had no significant impact on the levels of respiratory rate, heart rate, blood pressure, ECG, ALT or AST. Compared with the sham group, the serum levels of ALT and AST were increased significantly in the surgical groups. PHC alleviated all the biochemical and histopathological changes in a dose-dependent manner. The ALT and AST levels in the high-dose PHC-treated groups were significantly lower than those in the vehicle control group.Conclusion: Treatment with penehyclidine hydrochloride could improve liver function during CPB. [ABSTRACT FROM AUTHOR]

In developing low-temperature cofired ceramic (LTCC) technology for high-density packaging or advanced packaged electronics, matching the coefficient of thermal expansion (CTE) among the packaged components is a critical challenge to improve reliability. The CTEs of solders and organic laminates are usually larger than 16.0 ppm of °C 1- , while most low-permittivity (ε r ) dielectric ceramics have CTEs of less than 10.0 ppm °C 1- . Therefore, a good CTE match between organic laminates and dielectric ceramics is required for further LTCC applications. In this paper, we propose a high-CTE BaSO 4 -BaF 2 LTCC as a potential solution for high-reliability packaged electronics. The BaSO 4 -BaF 2 ceramics have the advantages of a wide low-temperature sintering range (650-850 °C), low loss, temperature stability, and Ag compatibility, ensuring excellent performance in LTCC technology. The 95 wt %BaSO 4 -5 wt %BaF 2 ceramic has a ε r of 9.1, a Q × f of 40,100 GHz @11.03 GHz ( Q = 1/tan δ), a temperature coefficient of the resonant frequency of -11.2 ppm °C 1- , a CTE of +21.8 ppm °C 1- , and a thermal conductivity of 1.3 W mK -1 when sintered at 750 °C. Furthermore, a dielectric resonant antenna using BaSO 4 -BaF 2 ceramics, a typically packaged component of LTCC and laminate, was designed and used to verify the excellent performance by a gain of 6.0 dBi at a central frequency of 8.97 GHz and a high radiation efficiency of 90% over a bandwidth of 760 MHz. Good match and low thermal stress were found in the packaged components of BaSO 4 -BaF 2 ceramics, organic laminates, and Sn-based solders by finite element analysis, proving the potential of this LTCC for high-reliability packaged electronics.

Objectives: To analyze the risk factors of sulfur hexafluoride microbubble contrast agent intravasation during hysterosalpingo-contrast sonography (HyCoSy), and to explore a simple prediction model by the obvious clinical history., Methods: This was a retrospective study included 299 infertility women who had undergone HyCoSy examination from July 1, 2018 to June 31, 2019. The factors were recorded, including age, endometrial thickness, balloon length, infertility type, history of intrauterine surgery, history of pelvic surgery, and tubal patency. The method of multivariate logistic regression analysis was adopted to analyze the risk factors affecting the contrast agent intravasation, and the receiver operating characteristic curves were plotted to test their efficacy., Results: Secondary infertility, a history of intrauterine surgery, thin endometrial thickness, and tubal obstruction were all risk factors of the occurrence of intravasation (P < .05). And the area under the receiver operating characteristic curves of the multifactor-combined prediction model of the intravasation was significantly larger than that of single-factor., Conclusions: Sonographers and gynecologists should be familiar with the risk factors of intravasation and select the appropriate timing of HyCoSy toward reducing the occurrence of intravasation and other complications after thoroughly explaining and communicating with the patients., (© 2023 American Institute of Ultrasound in Medicine.)

We propose a simulation method for a multireflector terahertz imaging system. The description and verification of the method are based on an existing active bifocal terahertz imaging system at 0.22 THz. Using the phase conversion factor and angular spectrum propagation, the computation of the incident and received fields requires only a simple matrix operation. The phase angle is used to calculate the ray tracking direction, and the total optical path is used to calculate the scattering field of defective foams. Compared with the measurements and simulations of aluminum disks and defective foams, the validity of the simulation method is confirmed in the field of view of 50 cm × 90 cm at 8 m. This work aims to develop better imaging systems by predicting their imaging behavior for different targets before manufacturing.

Objective: To evaluate the value of ultrasound-based radiomics in the preoperative prediction of type I and type II epithelial ovarian cancer., Methods: A total of 154 patients with epithelial ovarian cancer were enrolled retrospectively. There were 102 unilateral lesions and 52 bilateral lesions among a total of 206 lesions. The data for the 206 lesions were randomly divided into a training set (53 type I + 71 type II) and a test set (36 type I + 46 type II) by random sampling. ITK-SNAP software was used to manually outline the boundary of the tumor, that is, the region of interest, and 4976 features were extracted. The quantitative expression values of the radiomics features were normalized by the Z-score method, and the 7 features with the most differences were screened by using the Lasso regression tenfold cross-validation method. The radiomics model was established by logistic regression. The training set was used to construct the model, and the test set was used to evaluate the predictive efficiency of the model. On the basis of multifactor logistic regression analysis, combined with the radiomics score of each patient, a comprehensive prediction model was established, the nomogram was drawn, and the prediction effect was evaluated by analyzing the area under the receiver operating characteristic curve (AUC), calibration curve and decision curve., Results: The AUCs of the training set and test set in the radiomics model and comprehensive model were 0.817 and 0.731 and 0.982 and 0.886, respectively. The calibration curve showed that the two models were in good agreement. The clinical decision curve showed that both methods had good clinical practicability., Conclusion: The radiomics model based on ultrasound images has a good predictive effect for the preoperative differential diagnosis of type I and type II epithelial ovarian cancer. The comprehensive model has higher prediction efficiency., (© 2022. The Author(s).)

Objectives: To analyze the relationship between etiology and morphological classification of benign central airway stenosis and its prognosis. Methods: We performed a retrospective study of the medical records of 453 patients initially diagnosed with benign airway stenosis at Department of Respiratory Diseases in Beijing Tiantan Hospital affiliated to Capital Medical University from January 2003 to October 2019. Of 453 patients, 260 were male. The age of the study population was 12-86(44.0±24.5) years. Results: Among the 453 patients diagnosed with benign central airway stenosis, 161 case (35.5%, including 113 post-tracheostomy tracheal stenosis and 48 post-intubation tracheal stenosis) were iatrogenic; 88 cases were from benign tumors (19.4%), 77 cases from tracheal or bronchial tuberculosis (17.0%), 71 case from tracheal foreign bodies (15.7%). Disease causes varied among different gender or age groups. The main type of stenosis was structural stenosis, of which 241 cases (53.2%) were intra-luminal and 183 cases (40.4%) were scar contracture type. The site of stenosis showed a certain relationship with the causes of stenosis. The stenosis degree was mainly from grade 2 to grade 4 (76.4%), and the length was mainly within 3 cm (84.8%). Single factor analysis on the relationship between disease cause, morphological classification and prognosis of benign central airway stenosis showed statistically better prognosis in groups that were caused by benign tumor, intraductal stenosis or stenosis that were 3-4 in degree and 1-2 degree in length. Conclusion: The common causes of central airway stenosis included iatrogenic stenosis, benign tumor, tracheal or bronchial tuberculosis and tracheal foreign bodies. Benign airway stenosis with different disease causes and morphological classification had different prognosis after bronchoscopic interventional treatment. Clinicians should know the disease causes, morphological characterization and risk factors for benign airway stenosis for earlier diagnosis, treatment or prevention.

Microwave dielectric ceramics exhibiting a low dielectric constant ( ε r ), high quality factor ( Q × f ), and thermal stability, specifically in an ultrawide temperature range (from -40 to +120 °C), have attracted much attention. In addition, the development of 5G communication has caused an urgent demand for electronic devices, such as dielectric resonant antennas. Hence, the feasibility of optimizing the dielectric properties of the SmNbO 4 (SN) ceramics by substituting Bi 3+ ions at the A site was studied. The permittivity principally hinges on the contribution of Sm/Bi-O to phonon absorption in the microwave range, while the reduced sintering temperature results in a smaller grain size and slightly lower Q × f value. The expanded and distorted crystal cell indicates that Bi 3+ doping effectively regulates the temperature coefficient of resonant frequency (TCF) by adjusting the strains (causing the distorted monoclinic structure) of monoclinic fergusonite besides correlating with the permittivity. Moreover, a larger A-site radius facilitates the acquisition of near-zero TCF values. Notably, the (Sm 0.875 Bi 0.125 )NbO 4 (SB 0.125 N) ceramic with ε r ≈ 21.9, Q × f ≈ 38 300 GHz (at ∼8.0 GHz), and two different near-zero TCF values of -9.0 (from -40 to +60 °C) and -6.6 ppm/°C (from +60 to +120 °C), respectively, were obtained in the microwave band. A simultaneous increase in the phase transition temperature ( T c ) and coefficients of thermal expansion (CTEs) by A-site substitution provides the possibility for promising thermal barrier coating (TBC) materials. Then, a cylindrical dielectric resonator antenna (CDRA) with a resonance at 4.86 GHz and bandwidth of 870 MHz was fabricated by the SB 0.125 N specimen. The exceptional performance shows that the SB 0.125 N material is a possible candidate for the sub-6 GHz antenna owing to the advantages of low loss and stable temperature.

Objective: To analyze the efficacy and safety of Montgomery T-tube (T-tube) placement for benign complex subglottic tracheal stenosis. Methods: A retrospective analysis of the clinical data of 29 patients with benign complex subglottic tracheal stenosis receiving T-tube placement in Beijing Tiantan Hospital from May 2015 to December 2019. The causes were postintubation tracheal stenosis [27 cases (93.1%), including 21 cases (72.4%) of tracheal stenosis after tracheotomy, 6 cases (20.7%) of tracheal stenosis after tracheal intubation], cervical post-traumatic tracheal stenosis (1 case, 3.4%) and tuberculous tracheal stenosis (1 case, 3.4%), respectively. Three-dimensional reconstruction of tracheal computerized tomography (CT) and bronchoscopy were used to grade the stenosis according to Cotton-Myer classification system before bronchoscopic intervention. The degree of stenosis was Cotton-Myer grade Ⅱ (7 cases, 24.1%), grade Ⅲ (11 cases, 37.9%) and grade Ⅳ (11 cases, 37.9%), respectively. All cases received placement of T-tubes and follow-up. Fisher's exact test was used for comparison between groups. Results: T-tube placement was performed 39 times in 29 patients. T-tubes were successfully placed for 24 cases (82.8%). The main complication during the operation was tracheal mucosal tear (6 cases, 20.7%), which resolved in all cases within 2 weeks. The main postoperative complication was secretion retention (27 cases, 93.1%), which was relieved after home nebulization treatment in 26 cases; and followed by granulation hyperplasia, especially located in T-tube upper margin (12 cases, 41.4%), of which 8 cases were cured after bronchoscopic intervention. None of the patients had T-tube migration. There were no statistically significant differences in the success rate of T-tube placement and the incidence of major complications in patients with benign complex subglottic tracheal stenosis with different degrees of stenosis. After 18 months to 24 months of follow-up, attempt was made to remove the T-tube in 9 patients but failed in 4 patients. The failure was due to collapse of the airway after the T-tube was removed. Conclusion: T-tube placement is a safe and reliable treatment for benign complex subglottic tracheal stenosis with high efficiency and manageable complications.

Antimony tin oxide (ATO)/lead selenide (PbSe) composite was rationally designed and fabricated on fluorine doped tin oxide glass (FTO) for using as counter electrode (CE) of quantum dot sensitized solar cells (QDSSCs). The electrocatalytic activity of the CE is deeply investigated in the polysulfide electrolyte by employing the Tafel, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) of the symmetrical cells. The results confirm that the ATO/PbSe CE has better electrocatalytic activity and stability than that of PbSe CE obtained by pulse voltage electrodeposition (PVD). The enhanced electrocatalytic performance of ATO/PbSe CE can be attributed to its high specific surface area, excellent permeability, conductivity and interface connectivity, which provide more electrocatalytic active sites for the reduction of polysulfide species, as well as fast channels for ions diffusion and electron transport. As a result, the CdS QDSSCs and CdS/CdSe co-sensitized QDSSCs assembled by the ATO/PbSe CE exhibits better power conversion efficiency (η) of 1.72% and 5.59%, respectively than that of PbSe CE obtained by PVD. Furthermore, photovoltaic property of the ATO/PbSe CE in CdS/CdSe co-sensitized QDSSCs keeps stable for over 200 min. This present work provides a simple and effective strategy for the construction of high-performance CE materials of QDSSCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The charge recombination on the interfaces of TiO 2 /quantum dots (QDs)/electrolyte is a key factor limiting the efficiency of quantum dot-sensitized solar cells (QDSSCs). Construction of double-layer barrier structure of ZnS/QDs/ZnS is a vital strategy to suppress the interfacial charge recombination. However, a large lattice mismatch (12%) at CdSe/ZnS interfaces causes CdSe to grow slowly on TiO 2 /ZnS mesoporous film, weakening the interaction between QDs and mesoporous film, which reducing the efficiency of CdSe QDSSCs with double ZnS barrier layers. Applying a voltage of 2 V in successive ionic layer adsorption reaction (VASILAR) to create an electric field, which assists Cd 2+ and SeSO 3 2- ions rapidly diffuse into the TiO 2 /ZnS mesoporous film to react forming CdSe QDs at room temperature. Optimizing the number of CdSe QDs deposition layers and combine with ZnS double-layer barrier structure, a best PCE of 4.34% for ZnS/CdSe/ZnS QDSSCs is achieved. This study gives a fast and simple approach to inhibit interfacial charge recombination to construct high performance CdSe QDSSCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Terahertz (THz) spectroscopy has emerged as an attractive technique for qualitative and quantitative detection. Analysis of these chemicals in the THz range under various temperatures can yield detailed information on molecular vibrational modes, which is of utmost importance for effective detection. Here we report the use of THz time-domain spectroscopy (THz-TDS) to measure tetracyclines hydrochloride (TCH) and its degradation products including epitetracycline hydrochloride (ETCH), anhydrotetracycline hydrochloride (ATCH), and epianhydrotetracycline hydrochloride (EATCH) over the temperature range of 4.5-300 K for the first time. The results showed that these four tetracyclines exhibited numerous distinct spectral features in frequency-dependent absorption spectra, which demonstrated the qualitative capacity of THz-TDS. Through density functional theory (DFT) calculations and analysis of temperature-dependent absorption spectra, the origin of the observed terahertz absorption peaks of these four tetracyclines were well interpreted. This study could lay the foundation for high-performance analysis of biological and chemical molecules by THz spectroscopy, which is essential for sensing application., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Anemia is one of the most common complications of sepsis. Sepsis-related anemia is associated mainly with inflammation. We aimed to observe the changes in the inflammatory anemia-associated parameters of patients with sepsis in the early stage of intensive care unit (ICU) admission and to evaluate their association with 28-day mortality., Methods: A total of 198 patients with sepsis were divided into survivor (n = 110) and non-survivor (n = 88) groups on the basis of 28-day survival. Healthy volunteers (n = 20) were enrolled as a control group. Plasma levels of iron, ferritin, erythropoietin (EPO), soluble transferrin receptor (sTfR), hepcidin, interleukin-6 (IL-6), hemoglobin and the red blood cell distribution width (RDW) were measured on days 1, 3 and 7 of ICU admission. Clinical data and laboratory findings were collected, and the Sequential Organ Failure Assessment (SOFA) score was calculated., Results: Patients with sepsis showed significant decreases in hemoglobin, plasma iron and sTfR/log ferritin and significant increases in plasma EPO, sTfR, hepcidin, ferritin and IL-6 on days 1, 3 and 7 of ICU admission compared with healthy volunteers. Hemoglobin was correlated negatively with plasma IL-6 and hepcidin. In patients with sepsis, non-survivors had significantly lower plasma iron, EPO and sTfR/log ferritin, but higher plasma hepcidin, ferritin and IL-6 than survivors on days 1, 3 and 7 of ICU admission. Plasma EPO, hepcidin, ferritin, IL-6, sTfR/log ferritin, the RDW and SOFA score were associated significantly with 28-day mortality but to a varying extent. In particular, in predicting 28-day mortality, plasma hepcidin had an area under the receiver operating curve of 0.808 and 87.3% specificity, which was the highest among the inflammatory anemia-associated parameters tested., Conclusions: Inflammatory anemia-associated parameters changed significantly in patients with sepsis in the first week of ICU admission. Plasma EPO, hepcidin, ferritin, IL-6, sTfR/log ferritin, the RDW and SOFA score were associated significantly with 28-day mortality. Plasma hepcidin might have a superior predictive value, with high specificity, compared with other inflammatory anemia-associated parameters for 28-day mortality of sepsis patients in the ICU.

Cryptogenic organizing pneumonia (COP) is a rare pulmonary disorder of unknown etiology. COP with hemoptysis as the primary presenting symptom has rarely been reported. The present study reported a case of COP that resembled lung carcinoma with hemoptysis as the only clinical symptom. The patient recovered well following thoracoscope surgery. A literature review of 119 COP cases between 1995 and 2015 was presented. Cough, fever and dyspnea were the most common clinical manifestations. The most common imaging manifestations were multiple or single consolidation, lung nodules, migratory sign, reversed halo sign, and multiple ground-glass opacity. A total of 3 cases exhibited COP accompanied by lung cancer. Glucocorticoids were effective for the majority of cases and invasive surgeries were implemented in most cases. The majority of cases recovered or relieved, and the prognosis of COP was relatively good. COP was easily confused with lung tumor and it is necessary to make differential diagnosis between COP and lung cancer. Invasive surgery should be avoided when possible to avoid or reduce patient trauma.

Superconductor is a compelling plasmonic medium at terahertz frequencies owing to its intrinsic low Ohmic loss and good tuning property. However, the microscopic physics of the interaction between terahertz wave and superconducting plasmonic structures is still unknown. In this paper, we conducted experiments of the enhanced terahertz transmission through a series of superconducting NbN subwavelength hole arrays, and employed microscopic hybrid wave model in theoretical analysis of the role of hybrid waves in the enhanced transmission. The theoretical calculation provided a good match of experimental data. In particular, we obtained the following results. When the width of the holes is far below wavelength, the enhanced transmission is mainly caused by localized resonance around individual holes. On the contrary, when the holes are large, hybrid waves scattered by the array of holes dominate the extraordinary transmission. The surface plasmon polaritions are proved to be launched on the surface of superconducting film and the excitation efficiency increases when the temperature approaches critical temperature and the working frequency goes near energy gap frequency. This work will enrich our knowledge on the microscopic physics of extraordinary optical transmission at terahertz frequencies and contribute to developing terahertz plasmonic devices.

A novel series of microwave dielectric ceramics (Na0.5xBi0.5xCa1-x)MoO4 (0 ≤ x ≤ 0.6) was synthesized by the solid state reaction method. The crystal structures, microstructures, dielectric responses, and vibrational properties were investigated using X-ray diffraction, scanning electron microscopy, a microwave network analyzer, and terahertz, Raman and infrared spectroscopies. All the samples could be sintered well below 850 °C and a scheelite solid solution could be formed without any secondary phase. At x = 0.5 and x = 0.6, low-firing (750-775 °C) high performance microwave dielectric materials were obtained with permittivities of 19.1-21.9, Q × f values of 20 660-22 700 GHz, and near-zero temperature coefficients. The factors affecting microwave dielectric properties were discussed based on the vibrational data. As revealed by Raman spectroscopy, the disorder degree grows with x rising, which might increase the permittivities and decrease the Q × f values. The infrared spectra were analyzed using the classical harmonic oscillator model, and the complex dielectric responses gained from the fits were extrapolated down to the microwave and THz range. It is believed that the external vibration modes located at low frequencies dominate the main dielectric polarization contributions, especially the Na-O/Bi-O translational mode. This result indicates that the microwave dielectric properties of (Na0.5xBi0.5xCa1-x)MoO4 ceramics mainly depend on the behavior of AO8 polyhedra.

Objective: To improve understanding of the clinical characteristics and diagnosis of hypersensitivity pneumonitis (HP)., Methods: We retrospectively analyzed the clinical data, including clinical symptoms, laboratory tests, exposure, pulmonary function tests, chest CT imaging and cytological classification of bronchoalveolar lavage (BAL) of 96 patients with HP from Jan 2001 to Jun 2011 in Peking Union Medical College Hospital. We divided the patients into 2 groups: a pathologically-confirmed group and a clinically-suspected group., Results: There were 58 females and 41 males. The median age at the diagnosis was 53 years. The most common exposures were low-molecular-weight chemicals (42.7%) and animal proteins (37.5%). Common clinical symptoms included dyspnea on exertion (90.6%) and cough (76.0%). Pulmonary function test showed diffusion abnormality (73.5%) and restrictive ventilatory impairment (59.7%). Chest CT scan revealed patchy or diffuse bilateral ground-glass opacities (64.6%), centrilobular nodules (21.9%), and air trapping (15.6%). Reticulation (45.8%), traction bronchiectasis (21.9%) and honeycombing(9.4%) were present in chronic HP. BAL lymphocyte counts > 0.2 and CD4/CD8 < 0.9 were more commonly seen in patients with a disease course of less than 1 year. The pathologically-confirmed group and the clinically-suspected group shared many similar characteristics including age at diagnosis, gender, clinical manifestation, pulmonary function impairments and imaging findings, but significant differences existed in certain parameters. In the pathologically- confirmed group, the duration of disease was longer (24 months vs 6 months, Z = -2.492, P = 0.013) and clubbed fingers were more common (23.4% vs 8.2%, χ(2) = 4.227, P = 0.040). Diffusion abnormality was present in more patients of this group (90.7% vs 44.0%, χ(2) = 35.219, P < 0.01). By CT scan, reticulation, traction bronchiectasis and honeycombing (57.5% vs 26.5%, χ(2) = 9.434, P < 0.01) were more evident as compared to the clinically-suspected group. The value of transbronchial lung biopsy for diagnosing HP was limited, with a positive result of only 8.2%. Surgical lung biopsy was needed in uncertain cases., Conclusion: The diagnosis of HP was difficult. In some cases a clinical diagnosis can be made by combination of history of exposure, CT manifestations and cell classification of BAL. For atypical cases a multi-disciplinary approach including pathologists, radiologists and pulmonologists is needed.

This paper reports a type of low Ohmic loss terahertz (THz) metamaterials made from low-temperature superconducting niobium nitride (NbN) films. Its resonance properties are studied by THz time domain spectroscopy. Our experiments show that its unloaded quality factor reaches as high as 178 at 8 K with the resonance frequency at around 0.58 THz, which is about 24 times that of gold metamaterial at the same temperature. The unloaded quality factor keeps at a high level, above 90, even when the resonance frequency increases to 1.02 THz, which is close to the gap frequency of NbN film. All these experimental observations fit well into the framework of Bardeen-Copper-Schrieffer theory and equivalent circuit model. These new metamaterials offer an efficient way to the design and implementation of high performance THz electronic devices.

In the present paper the terahertz time-domain spectroscopy (THz-TDS) was used to measure the absorption spectra of L-, D-, DL-alpha-alanine at room temperature. A number of well-resolved absorption peaks were observed in the range of frequencies from 0.3 to 3.1 THz, which showed large differences in the spectra between the enantiomers (L-, D-alanine) and the racemic compound (DL-alanine). In parallel with the experimental study, the computed vibrational spectra were also obtained by using first principles calculations based on the density functional theory(DFT), which were in good agreement with the experimental data. Results show that the absorption spectra in terahertz region originate from the collective vibration based on hydrogen bonds.

Objective: To study the clinical characteristics and diagnosis of primary ciliary dyskinesia (PCD)., Methods: Four cases diagnosed as PCD by cilia electron microscopy examination from Jan. 2007 to Aug. 2009 in this hospital were retrospectively analyzed, and the related literature was reviewed., Results: In the 4 patients, there were 1 male and 3 females. The age at disease onset was 0 - 10 years, and the age at diagnosis was 15 - 53 years. The most common symptoms were productive cough (4/4), sinusitis (3/4), and shortness of breath (3/4). Other manifestations included situs inversus (2/4), infertility (1/4), and tympanitis (1/4). Hypoxemia was found in 3 cases. Obstructive ventilatory impairment accompanied with diffusion dysfunction was observed in 2 cases, while the pulmonary function tests were normal in the other 2 cases. All 4 cases received chest CT scan, and bronchiectasis was present in all of them. Bilateral diffuse micronodules and patchy infiltrates were found in 3 and 2 cases respectively. Electron microscopic examination of the endobronchial biopsy specimen showed lack of dynein arms in 4, lack of muco-cilia in 2, and abnormal arrangement of microtubules in 2 cases., Conclusions: The Kartagener syndrome is relatively easy to be diagnosed, because it is characterized by the triad of sinusitis, bronchiectasis and situs inversus. However, PCD without situs inversus often goes unrecognized. PCD should be considered in patients with childhood onset disease, bronchiectasis, centrilobular micronodules or tree-in-bud signs in CT scan. Examination of the ciliary ultrastructure is essential to the confirmation of the diagnosis.

Terahertz time-domain spectroscopy (THz-TDS), which directly measures the THz wave's temporal electric field, can give the amplitude and phase of the THz wave pulse simultaneously. THz-TDS is attracting more attention among scientists. InP with short carrier average collision time and low effective mass is growing up as one of the best photoconductive materials for emitting and detecting THz waves. An n-type InP of 0.35 omega x cm was characterized over the range from 0.2 to 4 THz at room temperature in the present paper with THz time-domain spectroscopy, which was placed in a closed box purged with dry nitrogen gas. Some THz optical properties, such as complex refractive index, dielectric constant, and conductivity, were extracted, based on more exact iterative method with new initial function. Drude model was also applied for simulation, which fitted well with the experimental results. Finally, the carrier average collision time, density and mobility of the InP were also characterized.

The temperature dependence of the real part of the microwave complex conductivity at 17.9 GHz obtained from surface impedance measurements of two c-axis oriented MgB2 thin films reveals a pronounced maximum at a temperature around 0.6 times the critical temperature. Calculations in the frame of a two-band model based on Bardeen-Cooper-Schrieffer (BCS) theory suggest that this maximum corresponds to an anomalous coherence peak resembling the two-gap nature of MgB2. Our model assumes there is no interband impurity scattering and a weak interband pairing interaction, as suggested by band structure calculations. In addition, the observation of a coherence peak indicates that the pi band is in the dirty limit and dominates the total conductivity of our films.