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Background According to the World Health Organization, China is one of 22 countries with serious tuberculosis (TB) infections and one of the 27 countries with serious multidrug-resistant TB strains. Despite the decline of tuberculosis in the overall population, healthcare workers (HCWs) are still at a high risk of infection. Compared with high-income countries, the TB prevalence among HCWs is higher in low- and middle-income countries. Low-dose computed tomography (LDCT) is becoming more popular due to its superior sensitivity and lower radiation dose. However, there have been no reports about active pulmonary tuberculosis (PTB) among HCWs as assessed with LDCT. The purposes of this study were to examine PTB statuses in HCWs in hospitals specializing in TB treatment and explore the significance of the application of LDCT to these workers. Methods This study retrospectively analysed the physical examination data of healthcare workers in the Beijing Chest Hospital from September 2012 to December 2015. Low-dose lung CT examinations were performed in all cases. The comparisons between active and inactive PTB according to the CT findings were made using the Pearson chi-square test or the Fisher’s exact test. Comparisons between the incidences of active PTB in high-risk areas and non-high-risk areas were performed using the Pearson chi-square test. Analyses of active PTB were performed according to different ages, numbers of years on the job, and the risks of the working areas. Active PTB as diagnosed by the LDCT examinations alone was compared with the final comprehensive diagnoses, and the sensitivity and positive predictive value were calculated. Results A total of 1 012 participants were included in this study. During the 4-year period of medical examinations, active PTB was found in 19 cases, and inactive PTB was found in 109 cases. The prevalence of active PTB in the participants was 1.24%, 0.67%, 0.81%, and 0.53% for years 2012 to 2015. The corresponding incidences of active PTB among the tuberculosis hospital participants were 0.86%, 0.41%, 0.54%, and 0.26%. Most HCWs with active TB (78.9%, 15/19) worked in the high-risk areas of the hospital. There was a significant difference in the incidences of active PTB between the HCWs who worked in the high-risk and non-high-risk areas (odds ratio [OR], 14.415; 95% confidence interval (CI): 4.733 – 43.896). Comparisons of the CT signs between the active and inactive groups via chi-square tests revealed that the tree-in-bud, cavity, fibrous shadow, and calcification signs exhibited significant differences (P = 0.000, 0.021, 0.001, and 0.024, respectively). Tree-in-bud and cavity opacities suggest active pulmonary tuberculosis, whereas fibrous shadow and calcification opacities are the main features of inactive pulmonary tuberculosis. Comparison with the final comprehensive diagnoses revealed that the sensitivity and positive predictive value of the diagnoses of active PTB based on LDCT alone were 100% and 86.4%, respectively. Conclusions Healthcare workers in tuberculosis hospitals are a high-risk group for active PTB. Yearly LDCT examinations of such high-risk groups are feasible and necessary. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0274-6) contains supplementary material, which is available to authorized users.

Penaeidin-2 (Pen-2) is an important antimicrobial peptide derived from the Pacific white shrimp, Penaeus vannamei, and possesses both antibacterial and antifungal activities. Recent studies suggest that recombinant penaeidins show similar activities to the native Pen-2 protein. Previous researches have shown that some antimicrobial peptides (AMPs) exhibit cytotoxic activity against cancer cells. To date, there have been no studies on the antitumor effects of Pen-2. This study evaluated the potential of recombinant pen-2 (rPen-2) in the selective killing of kidney cancer cell lines ACHN and A498, and its action mechanism. MTT assays found the maximal growth inhibition of HK-2, ACHN and A498 cells treated with 100 μg/mL rPen-2 at 48 h was 13.2%, 62.4%, and 70.4%, respectively. DNA-specific fluorescent dye staining showed a high percentage of apoptosis on cancer cells. Flow cytometry revealed that the apoptosis rate of HK-2, ACHN and A498 cells was 15.2%, 55.2%, and 61.5% at 48 h respectively, suggesting that rPen-2 induced higher apoptosis rate in cancer cells than in HK-2 cells. Laser confocal scanning microscopy demonstrated that the plasma membrane was the key site where rPen-2 interacted with and destroyed tumor cells. Scanning electron microscopy showed the morphologic changes of the cell membranes of kidney cancer cells treated with rPen-2. These results suggest that rPen-2 is a novel potential therapeutic agent that may be useful in treating kidney cancers.

A multi-stage traveling-wave waveguide-based spatial power divider/combiner using waveguide-to-microstrip (Wg-Ms) probe-pair coupling structure is proposed and applied to the design of a broadband power-combined amplifier module at Ka-band. An eight-way passive back-to-back power divider-combiner with four-stage Wg-Ms probe-pair transitions has been designed, fabricated, and tested. The measured overall insertion loss is less than 1.5 dB from 28 to 40 GHz, which demonstrates the low-loss performance of the proposed multi-way dividing/combining structure. Based on the passive power divider/combiner, an eight-device power-combined amplifier has been implemented with eight broadband medium power amplifier chips. The measured small-signal gain of the amplifier is more than 18 dB and the output power at 1-dB gain compression (P-1 dB) is higher than 30 dBm in the frequency band of 28–40 GHz. Power combining efficiency is within the range of 76–88%. Furthermore, the performance degradation of the power-combined ...

To evaluate the efficacy of comprehensive interventions based on the three TCM patterns on symptoms and quality of life of COPD patients.An open-label, randomized, controlled trial.Four hospitals in China.352 patients were randomly divided into two groups. Patients in the trial group were given conventional Western medicine and Bu-Fei Jian-Pi granules, Bu-Fei Yi-Shen granules and Yi-Qi Zi-Shen granules respectively; patients in the control group were given conventional Western medicine. Data collection was performed at baseline, in the 3rd and 6th month during the treatment period, and the 12th month during the follow-up period.Symptoms, including cough, sputum, pant, chest tightness, short of breath, lassitude, cyanosis and symptom total score; quality of life, measured by the WHOQOL-BREF questionnaire and adult COPD quality of life questionnaire (COPD-QOL).Of the 352 patients, 306 fully completed the study. After treatment and follow-up, there were significant differences between two groups in the following: cough, sputum, pant, chest tightness, shortness of breath, lassitude score and symptom total score (P.05); physical, psychological, social and environment domain (P.05) of the WHOQOL-BREF; daily living ability, social activity, depression symptoms and anxiety symptoms domain (P.05) of the COPD-QOL. There were no differences between two groups in cyanosis and adverse events.Based on the TCM patterns, Bu-Fei Jian-Pi granules, Bu-Fei Yi-Shen granules and Yi-Qi Zi-Shen granules have beneficial effects on symptoms and quality of life of COPD patients.

White spot syndrome virus is a highly pathogenic virus that infects crayfish and other crustaceans. VP28 is one of its major envelope proteins, and plays a crucial role in viral infection. Cell-penetrating peptides are short peptides that facilitate cellular uptake of various molecular cargoes, and one well known example is TAT peptide from HIV-1 TAT protein. In this study, recombinant plasmids were constructed and transformed into Escherichia coli strain BL21 (DE3) to express TAT-VP28, VP28, TAT-VP28-EGFP and VP28-EGFP fusion proteins. Enzyme-linked immunosorbent assay (ELISA) and flow cytometry methods were used to confirm that TAT fusion proteins can translocate from the intestine to the hemolymph of the crayfish Cambarus clarkii. After immunization, activities of phenoloxidase and superoxide dismutase were analyzed, and it was found that rTAT-VP28 produced the most pronounced increase in both C. clarkii were vaccinated by oral administration of rTAT-VP28 and rVP28 for 7 and 14 days, and rTAT-VP28 resulted in the highest relative percent survival (RPS) (63.3% at 7 days, and 67.8% at 14 days), compared with rVP28 (44.4% at 7 days, and 53.6% at 14 days) following challenge with WSSV after the last day of feeding. This study reports the use of TAT-derived peptide as an oral delivery method of a subunit vaccine against WSSV in C. clarkii.

A fixed-tuned low conversion loss full E-band seventh-harmonic mixer is presented. Mixing diodes are arranged as a single balanced configuration so that the RF signal is only mixed with LO odd harmonics and the idle mixing products are reduced by half. By replacing the traditional stepped impedance resonator filter with a newly developed two-stage compact microstrip resonating cell filter, the length of the filter has declined 64%. Measurement results indicate that the conversion loss of the seventh-harmonic mixer is 21.5 ± 5 dB in the frequency range of 60-90 GHz.

The adaptive integral method is utilized to solve electromagnetic scattering and radiation problems of conducting surface-wire configurations. The method of moments (MoM) is applied to establish the integral equations where triangular type basis functions are used to represent the currents on surfaces and wires. Attachment mode has been used to model the surface-wire junction to ensure the current continuity. The resultant matrix system is then solved by an iterative solver where the adaptive integral method (AIM) is employed to reduce memory requirements and to accelerate the matrix-vector multiplications. Numerical results are presented to demonstrate the accuracy and efficiency of the present technique for the arbitrary surface-wire configurations

The equivalent T—network parameters of millimeter wave E—plane discontinuities of bilateral metal septa with finite conductivity are calculated by the method of lines. An efficient approach is presented to extend this numerical method to EM boundary value problems with imperfectly conducting metal boundaries parallel to the discretization lines. Numerical results of both equivalent reactances and resistances in the T—network are obtained. The insertion losses of a Ka—band filter are calculated based on the lossy equivalent circuit. Numerical results are in agreement with the published experimental results.

A chiroferrite is made from chiral objects immersed in a magnetically biased ferrite. A waveguide including a chiroferrite is anticipated to possess some novel features due to the presence of chirality in combination with anisotropy. In this paper, the propagation characteristics of a circular metal waveguide filled with a chiroferrite medium are investigated by an analytical procedure. The equations of relations between the transverse components and the longitudinal ones of electromagnetic fields in general chiroferrite waveguides are derived in a cylindrical coordinate system. The coupled wave equations for the longitudinal electric and magnetic fields are decoupled into two Helmholtz equations which are then solved analytically. The characteristic equation is formulated for the circular chiroferrite waveguide. Propagation constants varying with the structural and material parameters have been calculated for several lower chiral modes. A number of interesting features have been revealed by the numerical results.

To investigate the relationship between pathological abnormalities of placenta and small-for-gestational-age neonates.One hundred placentas of small-for-gestational-age (SGA group) and 200 appropriate-for-gestational-age (AGA group) with single living birth in third trimester were investigated by gross and microscopic examination. The AGA placentas were collected from 2 cases following every SGA placenta. All cases were collected from Shanghai Changning District Maternity and Infant Health Hospital from January 2010 to December 2011.The gestational week, neonatal birth weight, full-term neonatal birth weight, the preterm birth rate and vaginal spontaneous delivery rate were significantly lower in SGA group than that in AGA group (P0.002). Full-term placental volume, placental weight and fetal placental weight ratio were lower in SGA group than that in AGA group (P0.05). Unusual insertion and torsion of umbilical cord were more common in SGA group (P0.05). Syncytial knots increase, avascular villi and villous infarcts were significantly higher in SGA group (P0.005), but there were no significant difference between SGA group and AGA group in intervillous thrombi, chronic villitis and chorangiosis (P0.05). Gestational hypertension disease and abnormality of fetal monitoring were more common in SGA group (P0.05).Gestational hypertension disease is the main clinical cause of SGA. Some placental abnormality can affect the growth and development of intrauterine fetus.

A dual-diode millimeter wave harmonic power combiner in which two radial line transformers are used is modelled by a field analysis technique based on Galerkin's method combined with collocation technique. The external circuit impedances looking outside from each of two active devices are computed at both fundamental frequencies and the second harmonic frequencies. Numerical results of the impedances with respect to various structural parameters are presented. Some important characteristics of the harmonic power combiner are revealed. A number of useful conclusions have been deduced for practical design and adjustment.

Two mutually coupled radial line transformers mounted in a common rectangular waveguide of dual—diode millimeter wave oscillator are characterized by a hybrid technique based on Galerkin's method combined with collocation technique. The external circuit impedances looking outside from each of two active devices are calculated. A large number of numerical results of the external circuit impedances as a function of the structural parameters have been obtained. Some original conclusions have been made, which are helpful to the design and the adjustment of the dual—diode oscillators.

To investigate the relationship between partial reversed cell polarity (PRCP) and lymphatic tumor spread in invasive ductal carcinoma (IDC), not othervise specified (NOS).Immunohistochemistry (EnVision method) was used to examine the expression of epithelial membrane antigen (EMA) and the reversed cell polarity in 199 cases of IDC.Of the 199 cases, including five cases with micropapillary differentiation,30 cases with PRCP and 164 cases of IDC-NOS (without micropapillary differentiation and/or PRCP), lymphovascular invasion was seen in four (4/5), 13(43.3%) and 30 cases (18.3%) respectively; nodal metastasis was seen in four (4/5), 19 (63.3%) and 56 cases (34.1%) respectively. The rates of lymphovascular invasion and nodal metastasis were significantly higher in IDC with PRCP or IMPC than IDC-NOS (P = 0.00); there was however no significant difference between IDC with PRCP and IMPC for lymphovascular invasion and nodal metastasis (P = 0.18, P = 0.64).IDC with PRCP, similar to IMPC, is more likely to show lymphovascular invasion and nodal metastasis. Complete or partial reversal of cell polarity may play a significant role in lymphatic tumor spread.

Harmonic injection locking behavior of millimeter wave second harmonic Gunn oscillators is studied based on an equivalent circuit model. A large signal model of Gunn device in harmonic mode operation is employed. Injection locking curves of voltage amplitude and phase difference between injected current and harmonic voltage are calculated by means of describing function technique. Stability of the locked harmonic oscillators is also investigated. It is revealed that the harmonic locking bandwidth is much smaller than that of fundamental wave oscillators and is closely related to the susceptance slope parameter of fundamental wave circuit. It is also found that the stable region is smaller than that of fundamental wave oscillators. Some conclusions have been made for the application of harmonic injection locking technique.

To investigate the clinicopathological and immunohistochemical features of primary malignant tumor of the appendix.The clinical data were reviewed; and histopathological and immunohistochemical features were analyzed in 22 cases with primary malignant tumor of the appendix.In 22 cases of primary malignant tumor of the appendix, 19 cases were carcinoid and 3 were adenocarcinoma. Immunohistochemistry showed that the carcinoid was positively reacted to the neuroendocrine markers, and the adenocarcinoma was negatively reacted to the neuroendocrine markers.Immunohistochemistry is useful in diagnosis of primary malignant tumor of the appendix, a rare type of cancer.

Protective immune responses in shrimp induced by DNA vaccines against white spot syndrome virus (WSSV) with intramuscular injection have been reported in recent reports. In this study, we investigated the utilities of attenuated Salmonella enterica serovar Typhimurium (Salmonella typhimurium) as a bactofection vehicle for the oral delivery of a DNA vaccine plasmid to crayfish (Cambarus clarkii). The DNA vaccine plasmid pcDNA3.1-VP28, encoding viral envelope protein VP28, was transformed to an attenuated S. typhimurium strain SV4089 and the resulting recombinant bacteria named SV/pcDNA3.1-VP28 were used to orally immunize crayfish with coated feed. Successful delivery of the DNA vaccine plasmid was shown by the isolation of recombinant bacteria SV/pcDNA3.1-VP28 from the vaccinated crayfish. The distribution analysis of plasmid pcDNA3.1-VP28 in different tissues revealed the effective release of DNA vaccine plasmid into crayfish. RT-PCR and immunoflurescence results confirmed the expression of protein VP28 in the vaccinated crayfish. Challenge experiments with WSSV at 7, 15, 25 days post-vaccination demonstrated significant protection in immunized crayfish with relative survival rate 83.3%, 66.7% and 56.7%, respectively. Studies on stability and safety of SV/pcDNA3.1-VP28 showed the recombinant bacteria could exist in crayfish at least 7 days but not more than 10 days and without any observable harm to the host. Our study here demonstrates, for the first time, the ability of attenuated Salmonella as a live vector to orally deliver a DNA vaccine against WSSV into the arthropod crayfish and provides a new way to design more practical strategies for the control of WSSV and other invertebrate pathogens.

To investigate the difference of galectin-3 and CD44v6 expression between benign and malignant thyroid nodules, and to evaluate their clinical value in distinguishing thyroid cancer from benign thyroid nodules.The expression of galectin-3 and CD44v6 was immunohistochemically detected by the ABC method in 143 benign and malignant thyroid nodule samples.Expression of these two markers in benign thyroid nodules: galectin-3 was negative in 10 cases of para-cancer normal tissue and 14 cases of benign nodules found in the other benign thyroid disease. It was weakly positive in 4 of 52 nodular goiter (7.7%). Also it was weakly positive in 2 of 22 follicular adenomas (9.1%). But all three eosinophilic follicular adenomas were diffusely or focally positive for galectin-3. CD44v6 was negative in 10 cases of para-cancer normal tissue, but positive in 4 of 14 nodular lesions found in benign thyroid diseases (28.6%). It was also positive in 16 of 52 nodular goiters (30.8%), and weakly positive in 7 of 22 follicular adenomas (31.8%). The two markers in malignant lesions: galectin-3 was positive in 50 of 52 thyroid adenocarcinoma (96.2%), CD44v6 was positive in 42 of 52 thyroid adenocarcinoma (80.8%). The positive rate of galectin-3 and CD44v6 expression in thyroid cancer was significantly higher than that in benign thyroid nodule and normal tissue (P0.001). The sensitivity, specificity and accuracy of galectin-3 combined with CD44v6 in differentiating benign from malignant thyroid nodule were 80.8%, 93.4%, 88.8%; they were 96.2%, 90.1%, 92.3% for Galectin-3 alone.The immunohistochemical expression of galectin-3 and CD44v6 by the ABC method is significantly higher in thyroid cancers than in benign thyroid nodules, especially galectin-3 in thyrocyte being helpful in differentiating benign thyroid nodule from thyroid cancer.

This Two-layer surface fluxes model is suitable to inhomogenous soil-vegetation surface. The key step is to separate mixed pixel surface temperature. ATSR's sensor can provide two view angles for separating the temperature. However, the areas are different between the pixel at nadir view and the pixel at forward view, which would result in some errors. Furthermore, re-sampling will reduce the spatial resolution of remote sensing data. On the other hand, remote sensing data source used widely now do not provide multi-angular data, which also limits the wide use of this method. An alternative method for separating mixed pixel temperature is proposed in this paper. A different T-m2 similar to f(2) equation is established using the derivative of pixel mixed temperature to vegetation fractional cover (dT(m)/df). Combining with original T-m1 similar to f(1) equation the mixed pixel temperature can he separated. A pixel component arranging comparing method will be used to obtain (dTm/df). The essence of the method is to obtain (dTm/df) using slopes of a trapezium. The principle of this method is similar to the multi-angular method. And the method overcomes the uncertainty due to the different area measured in two view angles. Theoretical positioning algorithm of four extreme pixel temperatures in the trapezium is presented to overcome uncertainty of previous method. We did a series of experimentsin Beijing and Yucheng remote sensing experimental stations, and the results indicated that this algorithm is suitable for the purpose. The above methods were adopted to separate mixed pixel temperature in two-layer surface flux model using MODIS data and simultaneous measurements in Dongping Lake, Shandong province of China. Distribution images of soil evaporation and vegetation transpiration were obtained in North China. The method and algorithm are feasible and reasonable according to good agreements' between predicted and measured values.

In the micrometeorolotrical and microclimatic research fields, surface roughness length is one of the very important surface parameters in estimating surface fluxes. With the development of remote sensing models for retrieving surface fluxes, the concept and estimating method for surface roughness length has been developed correspondingly. This paper analyzed researcher's cognition process of the surface roughness length. An experiment was further carried out in 2004 to improve and validate Zhang's model, which was proposed in 2004. In this paper, roughness elements' geometric roughness length was retrieved on TM pixel scale, and aerodynamic surface roughness length under conditions of atmospheric stability was iterated out with field measured data. By choosing eight typical wind directions, we established a relationship between roughness elements' geometric roughness length and effective surface roughness length, which made quite an improvement for Zhang's model. The parameters of the model were optimized and more universal, and the model could be used universally. The result indicates further that effective roughness length of a certain g fetch is related closely to equivalent geometric roughness length of each pixel unit within the fetch area. The model for retrieving surface roughness length would help to improve the surface fluxes retrieval precision greatly.

First the paper discussed the importance of daily total evapotranspiration in hydrology, agriculture, forestry and environmental studies. Then the function relation between evaporative fraction and Bowen ratio was discussed based on energy balance without advection. Variation of Bowen ratio with time front China Ecosystem Research Network was classified into four types and the influential factors were analyzed. And daily total evapotranspiration was estimated based on the flux observations of the stations. The results showed that average error of about twelve percent was probably produced without considering variation of Bowen ratio with nine when retrieving daily total evapotranspiration. Finally the paper retrieved total evapotranspiration of North China Plain in DOY78, 2002 based on the hypothesis that Bowen ratio was unchanged in a day, a two-layer model and,MODIS data in combination with the weather data. The results showed that it is necessary to take variation of Bowen ratio with time into account to further improve the retrieval precision of daily total evapotranspiration based on remote sensing.

In the article, one universal formula presented by RH Zhang (2004) is validated based on the TM image assimilation and the surface simultaneous experiment data which was measured in remote sensing experimental field of Xiaotangshan of Beijing. Several scales was used to study: the first is the experimental field (2 m /spl times/ 2 m), another is a 30 m /spl times/ 30 m TM image validated by the experiment data, the others are images degraded using the Landsat TM image. The scaling rule of independent variables defined as those surface parameters whose values are not affected by its neighboring pixels but depend on the characteristics of the pixel itself, such as NDVI, albedo, LAI, surface emissivity and apparent thermal inertia (ATI). They are investigated using the areas composed by farmland, the areas of the same size but different water area fractions, within which the difference of the surface characteristics are obvious. Generally, the independent variables can be expressed as the form of x/y. Therefore, when degrading these parameters, the scaling rule have close relationship with the numerator x and the denominator y. In terms of our analysis, when the denominator y/sub i/ is the same for the aggregated pixels, there is no scaling difference. However, when y/sub i/ is variable, the scaling difference is affected by the magnitude of x and y, and the variance of x/sub i/ (varx) and y/sub i/ (vary) divided by the average x/sub i/ (meanx) and y/sub i/ (meany) can reduce this effect; for a moderate heterogeneous surface, the scaling difference of NDVI, LAI, emissivity and ATI can be ignored, however, for obvious contrasting surface, the scaling difference can lead to large errors; when the meanx, meany, varx and vary are in the same magnitude, it can be considered that there is the same scaling difference regardless of resolution.

First of all the paper discussed the action of objects' thermodynamic characteristics, environmental factors, microclimatological parameters, soil physical parameters, ecological parameters, especially sensible and latent heat exchange on thermal radiation exchange. Particularly, increase or decrease of the objects' temperature was mentioned when measuring thermal infrared multi-reflection in a non-isothermal system. Reflection radiation and emission radiation should be separated when extracting multi-reflection radiation information from measured signals of the thermal radiometer. And the applicability of Kirchhoff's law in a nonisothermal system should also be considered. On the base of above, an instrument for measuring thermal infrared multi-reflection was developed and a kind of algorithm was put forward for extracting reflection radiation from mixed thermal radiation information. We did field experiments for measuring thermal infrared multi-reflection in 2004. Experiments and results showed that measurement accuracy of twice-thermal reflection radiation in soil-vegetation system could meet the needs of the most models at present.

To validate the accuracy of remote sensing flux model and to test the sensitivities of parameters, one Large Aperture Scintillometer (LAS), one Eddy Covariance (EC) system and other supporting observations were used to estimate sensible heat flux of a typical natural surface. The remote sensing model is Surface Temperature - Resistance (STR) model. The results obtained from different spatial scales were inter-compared. It shows that (1) there are better changing trend of sensible heat fluxes obtained by LAS and EC and STR methods; (2) the remote sensing assessed sensible heat flux was a good agreement with measurements by using LAS and EC, HSTR is rough 8% larger than HLAS; (3) LAS is reliable to validate the pixel sensible heat flux derived by remote sensing model

The equivalent lossy T-network parameters of E-plane discontinuities (in rectangular waveguides) of bilateral metal septa with finite conductivity are calculated by the method of lines. An efficient approach is presented to extend this numerical method to EM boundary value problems with imperfectly conducting metal boundaries parallel to the discretization lines. Numerical results of both equivalent reactances and resistances in the T-network are obtained. The calculated insertion losses of a Ka-band filter based on the lossy equivalent circuit fit better with the published experimental results than what have been obtained based on a lossless equivalent circuit.