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Radar coincidence imaging is a new method for high-resolution staring imaging. First, the mathematical model is constructed. Second, the theoretical error for radar coincidence imaging in the presence of noise is derived using the parametric imaging method. Third, the factors that affect the error are analyzed. Fourth, the sparse reconstruction algorithm is used to perform numerical simulations of radar coincidence imaging with different parameters. Finally, the effects of signal bandwidth, array configuration, size of the imaging unit, and target complexity on image error in the presence of noise are discussed. This study provides the theoretical framework for parameters selection and SNR requirements for radar coincidence imaging systems.

Taken into consideration of the effect of rotor downwash and shrouding duct, the Pitt-Peters' first harmonic non-uniform dynamic inflow model is extended to modeling the rotor/ducted fan propellant system. Combined with the data of wind tunnel experiment of assembled fan and duct fuselage, a practical nonlinear mathematical model of a full-scale rotor/ducted-fan helicopter is derived. The derived nonlinear model is linearized and the analysis of flight dynamics of the rotor/ducted-fan helicopter is conducted. The analysis results are compared with the flight dynamics of a conventional helicopter. It is indicated that the distinguishing features of the rotor/ducted-fan helicopter from the conventional helicopter are predominantly in the stability of lateral-directional motion modes at different flight speeds and the coupling characteristics of response to control inputs. [ABSTRACT FROM AUTHOR]

The amplitude and phase characteristics of complex radar cross section (RCS) of a metallic sphere are analyzed based on the precise solution of its back scattering. The high resolution range profile of a sphere takes on one or two peaks at different bands, while its 2D image can be typified by an arc or a point at different bands and rotation angles. A sphere should be characterized by a dispersive, migratory or point-like scattering center model under different conditions. These conclusions may provide an important reference for RCS calibration and scattering source diagnosis. [ABSTRACT FROM AUTHOR]

Objective: To analyze the safety and effectiveness of 3D printing prefabricated nail path model assisted lumbosacral hemivertebra orthopaedic surgery., Methods: A retrospective analysis was performed on 8 patients with lumbosacral hemivertebra deformity admitted from January 2016 to July 2021, including 3 males and 5 females, aged 6 to 15 at the time of surgery. The hemivertebra of 4 cases located on the left side and 4 cases on the right side. The hemivertebra of 1 case located at L 2,3 , 2 cases at L 3,4 , 2 cases at L 4,5 , and 3 cases at L 5 S 1 . Four cases were fully segmented hemivertebra and 4 cases were incomplete segmented hemivertebra. The patient CT data was imported into Mimics 21.0 software for modeling, and then the model data was imported into 3-Matic software. The vertebra requiring screw placement was selected to simulate the optimal screw placement angle and length, and the model was printed for preoperative planning and intraoperative guidance. All patients underwent orthopedic surgery with the aid of 3D printing preset nail path model. The safety and effectiveness of the 3D printing prefabricated nail tunnel model assisted lumbosacral hemivertebra orthopaedic surgery was evaluated by comparing the imaging parameters of the patients. The main outcome measures were the Cobb angle of the main curve, the Cobb angle of the proximal compensatory curve, the coronal balance index C 7 plumb line-center sacral vertical line(C 7 PL-CSVL), the accuracy of nail placement, and the correction rate of scoliosis before surgery, 1 week and 1 year after surgery., Results: All of 8 patients were followed up for 13 to 31 months. A total of 98 pedicle screws were placed in 8 patients. The number of pedicle screw grades A, B, C, D, E was 38, 46, 10, 4, 0 screws. The screws of grade A and B were defined as good position, the accuracy rate of screw placement was 85.7%. The Cobb angle of the main curve were 21° to 38° before operation, 5° to 11° at 1 week after operation, 7°to 12° at 1 year after operation. The Cobb angle of the proximal compensatory curve were 16° to 39° befoer operation, 7° to 12 °at 1 week after operation, 7° to 14° at 1 year after operation, the correction effect remained good with no correction loss. The coronal balance index C7PL-CSVL were 20 to 35 mm before operation, 11 to 18 mm at 1 week after operation, 10 to 16 mm at 1 year after operation, the coronal imbalance improved. The scoliosis correction rate was 65.6% to 84.2% 1 week after surgery, and 61.9% to 81.6% 1 year after surgery., Conclusion: The use of 3D printing prefixed nail tunnel model in lumbosacral hemivertebra osteotomy is safe and effective, and can significantly improve patients' local deformities. It is a reliable method to assist lumbar sacral hemivertebra osteotomy.

Objective: To investigate the safety and clinical effect of testis-sparing microsurgery (TSMS) in the treatment of benign testis tumor (BTT)., Methods: We retrospectively analyzed the clinical data on 16 cases of BTT treated in the Department of Andrology of the Affiliated Hospital of Qingdao University from October 2020 to February 2023. The median age of the patients was 23 years. All the tumors were unilateral, 7 in the left and 9 in the right side, with a median diameter of 1.85 cm (1.0－3.5 cm). The patients all underwent color Doppler flow imaging (CDFI), MRI, semen analysis and examination of serum T, alpha-fetoprotein (AFP), human chorionic gonadotropin (HCG) and lactate dehydrogenase (LDH), followed by TSMS. The boundaries between the tumors and normal testis tissue were accurately identified under the microscope, and the tumors and the adjacent normal testis tissue 2 mm from their margins were excised completely. Bipolar coagulation forceps were used for wound hemostasis to maximally preserve the normal testis tissue. The resected specimens were subjected to fast frozen pathology intraoperatively, and the patients were followed up for 14－40 months by regular scrotal CDFI, MRI and examinations of serum T and semen parameters., Results: The levels of serum T, AFP, HCG and LDH and semen parameters were all within the normal range preoperatively. TSMS were successfully completed in all the cases, and all were pathologically confirmed as BTT according to the latest edition of WHO Classification of Tumors: Urinary and Male Genital Tumors. CDFI showed normal blood supply within the testis tissue at 1 month after surgery. No signs of intra-testicular tumor residue, recurrence or metastasis, nor significant changes in the levels of serum T, AFP, HCG or LDH or semen parameters were observed during the follow-up as compared with the baseline. Natural conception was achieved in 2 cases at 16 and 18 months respectively after surgery., Conclusion: BTT can be differentially diagnosed by CDFI and MRI before surgery and confirmed by histopathology. TSMS can achieve complete excision of the tumor, maximal sparing of the normal testis tissue and thereby effective preservation of male fertility.

Objective: To investigate the distribution of the gene subtypes of human papillomavirus (HPV) in male patients with condyloma acuminatum (CA) and analyze the characteristics of the gene subtypes., Methods: We extracted genomic DNA of the HPV virus from the genital tissue of 70 male CA patients, detected the DNA subtypes of HPV using the PCR-reverse dot hybridization technique, and analyzed the rates of different subtypes identified and their characteristics of distribution in different age groups., Results: The male HPV-positive patients were mainly infected at the age of 20－39 years, primarily with high- and low-risk mixed infection of various subtypes, which accounted for 61.54% in the 20- to 29-year-olds and 42.86% in the 30- to 39-year-olds. Among the 70 CA patients, 22 HPV subtypes were identified, the top five subtypes including HPV 11 (21.08%), HPV 6 (19.46%), HPV 42 (6.49%), HPV 59 (6.49%) and HPV 53 (5.95%); 20 infected with a single subtype (28.57%), 19 with two subtypes (27.14%) and 31 with three or more (44.29%); and 30 infected with a low-risk single subtype (42.86%) and 40 with both high- and low-risk multiple subtypes (57.14%)., Conclusions: Male patients with CA are mainly infected with HPV 11 and HPV 6, with a significantly higher rate of multi-subtype than single-subtype infection, and the multi-subtype patients chiefly with high- and low-risk mixed infection. Men aged 20－39 years old are most commonly affected by CA.

Objective: To observe the influence of different concentrations of bisphenol A (BPA) on glucose metabolism and lactate dehydrogenase (LDH) expression in rat Sertoli cells in vitro and investigate the mechanisms of BPA inducing male infertility., Methods: Using two-step enzyme digestion, we isolated Sertoli cells from male Wistar rats and constructed a primary Sertoli cell system, followed by immunohistochemical FasL staining. We randomly divided the Sertoli cells into a control group to be cultured in the serum-free minimal essential medium (MEM) plus dimethyl sulfoxide (DMSO) and three experimental groups to be treated with 100 nmol/L, 10 μmol/L, and 1 mmol/L BPA, respectively, in the MEM plus DMSO. After 48 hours of treatment, we measured the proliferation of the cells by CCK-8 assay, determined the concentrations of metabolites by NMR spectroscopy, and detected the expression of LDH in the Sertoli cells by RT-PCR and Western blot., Results: The purity of the isolated Sertoli cells was (96.05 ± 1.28)% (n = 10). Compared with the control group, the 100 nmol/L, 10 μmol/L, and 1 mmol/L BPA groups showed no remarkable changes in the proliferation of Sertoli cells ([98 ± 8]%, [96 ± 3]%, and [95 ± 3]%, P >0.05), but the 10 μmol/L and 1 mmol/L of BPA groups exhibited significantly decreased concentrations of intracellular glucose ([3.89 ± 0.07] vs [3.36 ± 0.24] and [3.04 ± 0.21] pmol/cell, P <0.05) and lactate ([0.43 ± 0.06] vs [0.29 ± 0.05] and [0.20 ± 0.03] pmol/cell, P <0.05). The expression of LDH mRNA was decreased with the increased concentration of BPA, while that of LDH protein reduced only in the 1 mmol/L BPA group (P <0.05)., Conclusion: High-concentration BPA decreases the expression of LDH and alters glucose metabolism in Sertoli cells, and therefore may reduce the provision of lactate for germ cells and impair spermatogenesis.

The variations of black carbon (BC) mass concentration in Shanghai are analyzed and discussed by using hourly averaged data monitored continuously at Shanghai Urban Environmental Meteorological Center from January 2008 to December 2012. The results show that the annual mean mass concentration of BC decreased from (4 045.3 +/- 3 375.4) ng x m(-3) in 2008 to (2 766.2 +/- 2 078.9) ng x m(-3) in 2012, and the annual changes are 2.3%, - 6.5%, -18.7% and -12.1%, respectively. The yearly averaged BC mass concentration in Shanghai is on the low side of middle-level compared with other mega-cities of China. According to the test data,the highest monthly averaged concentration of BC appeared in November and December,which were 5 426.6 ng x m(-3) and 5 365.3 ng x m(-3), respectively,and then in January, June and October, which were 4402.5, 3763.3 and 3412.7 ng x m(-3), respectively. The diurnal cycles of the BC mass concentration show that there are two obvious peaks during morning 07:00-10:00 and during evening 18:00-22:00 Beijing time (BT), and the first peak was higher than the second on weekdays, but opposite on weekends and holidays. The daily mean mass concentration of BC was 9% higher on weekdays than on weekends and holidays. In addition, an empirical equation is obtained for daily BC concentration estimation and prediction using all the effective test data during the 5-year observation period and employing the regression analysis.

Objective: To explore the mechanism of hyperthermia inducing infertility by observing the expression of glial cell line-derived neurotrophic factor (GDNF) in rat Sertoli cells cultured in vitro at different temperatures., Methods: Using combination enzyme digestion and selective adhesion, we isolated Sertoli cells from male Wistar rats and cultured them in vitro at different temperatures, followed by observation of the changes in their adhesion and morphology and identification by FasL immunohistochemical staining. We divided the Sertoli cells into a control group (35 degrees C) and four experimental groups (36 degrees C, 37 degrees C, 38 degrees C, and 39 degrees C), measured their proliferation by CCK-8, observed their morphology and structure by HE staining, and determined the expression of GDNF by RT-PCR, immunofluorescence and Western blot., Results: Sertoli cells were successfully isolated and in vitro-cultured, with a purity of (95.30 +/- 2.15)% (n = 10). The CCK-8 assay showed that the proliferation of the Sertoli cells was the highest at 36 degrees C, gradually decreasing with the temperature above 36 degrees C, and significantly inhibited at 39 degrees C (P < 0.01). Immunofluorescence revealed the expression of GDNF in the cytoplasm, with the highest fluorescence intensity at 36 degrees C. RT-PCR and Western blot exhibited a decreasing trend of the GDNF expression with the increasing temperature above 36 degrees C. There were statistically significant differences in the expression of GDNF between the control group and the four experimental groups (P < 0.01)., Conclusion: The proliferation and GDNF expression of in vitro-cultured Sertoli cells differ significantly at different temperatures. At > 36 degrees C, the higher the temperature is, the lower the Sertoli cell proliferation and GDNF expression are. Our findings suggest that high temperature above 36 degrees C suppresses the function of Sertoli cells and may also damage spermatogenesis.

Objective: To investigate the effect of hypoxia on the proliferation and occludin expression of primary rat Sertoli, Methods: We constructed a primary Sertoli cell system by two-step enzymatic digestion in 18 -22 days old Wistar rats and identified it by oil red O and immunofluorescence methods. We randomly divided the Sertoli cells into five groups to be cultured in oxygen at the concentrations of 20%, 15%, 10%, 5% and 1%, respectively, for 6, 12, 24, 48 and 72 hours. We detected the proliferation of the Sertoli cells by CCK-8 assay, determined the expression of occludin by Western blot, and analyzed the differences among the five groups., Results: Oil red O staining revealed red lipid droplets in the cytoplasm of the Sertoli cells, and immunofluorescence showed the positive expression of the FasL protein, with the purity of Sertoli cells over 95% in vitro. Compared with the 20% normoxic group, the proliferation of the Sertoli cells was gradually reduced in the 15% and 10% hypoxia groups, and significantly declined in the 5% and 1% groups (P < 0.01). At 12 hours, the expression of occludin began to decrease with the prolonging of time and reduction of oxygen concentration (P < 0.01)., Conclusion: Hypoxia suppresses the proliferation of Sertoli cells and reduces the expression of occludin. It could be inferred that hypoxia could damage the integrity of blood-testis barrier and spermatogenesis of the testis.

Objective: Primary premature ejaculation (PPE) is a prevalent sexual dysfunction among men while its precise pathologic mechanism has remained poorly understood. In current study the correlation between excitability of bulbocavernosus reflex (BCR) to stimulation of prostatic urethra and primary premature ejaculation was studied., Methods: Forty-two patients with PPE and 20 normal potent male volunteers were studied by inserting a specially designed Foley catheter with two electrodes mounted on its distal surface (intraurethral catheter electrode) into bladder to evoke the BCR to stimulation of prostatic urethra to record the sensory thresholds of BCR to stimulation of prostatic urethra, thresholds to evoke stable BCR and latencies of BCR. Also the sensitivity of glans penis to electrical stimulation was detected by two surface electrodes., Results: The mean sensory thresholds of BCR to stimulation of prostatic urethra, thresholds to evoke stable BCR, latencies of BCR and sensory thresholds of glans penis were (18.2 +/- 2.7) mA (0.2 ms in duration, 1 Hz), (34.8 +/- 4.2) mA (0.2 ms, 1 Hz), (71.2 +/- 5.8) ms and (14.2 +/- 1.9) mA (0.04 ms in duration, 3 Hz) in normal potent men respectively and were (12.4 +/- 3.7) mA (0.2 ms, 1 Hz), (23.8 +/- 5.6) mA (0.2 ms, 1 Hz), (70.5 +/- 6.3) ms and (11.9 +/- 2.3) mA (0.04 ms, 3 Hz) in patients with PPE respectively. Statistically significant differences were seen regarding the sensory thresholds of BCR to stimulation of prostatic urethra, the thresholds to evoke stable BCR and the sensory thresholds of glans penis between two groups (all P < 0.01). No statistically differences were seen regarding the latencies of BCR between two groups (P > 0.05)., Conclusion: Patients with PPE have hyperexcitable BCR to stimulation of prostatic urethra. It is probably one of the important etiological factors. Moreover the findings may provide new therapeutic modalities of PPE.

Objective: To evaluate the contribution of platelet and leukocyte activation in pathogenesis primary pulmonary hypertension (PPH)., Methods: Pulmonary hypertension was induced by subcutaneous injection of 2% monocrotaline (MCT) in male Prague-Dawley (SD) rats. Blood samples were collected at the third week after MCT injection, and flow cytometry was used to determine the fibrinogen-binding platelet, CD11b expression on leukocyte and platelet-leukocyte aggregation., Result: Three weeks after MCT injection, rats exhibited higher right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure(mPAP), as compared with controls. MCT induced vascular remodeling characterized by vascular medial wall thickening in pulmonary muscular arteries. The ratio of platelets fibrinogen binding was increased in rats 3 weeks after MCT injection than that of control group[(4.08 +/-1.59)% compared with (1.45 +/- 0.61)%, P<0.01]. CD11b expression in monocytes and neutrophils, but not in lymphocytes was increased significantly 3 weeks after MCT injection (P <0.01). Platelet-neutrophil aggregations increased in MCT injected rats as compared with controls (P <0.01)., Conclusion: Rats of PPH model demonstrate enhanced circulating platelet and leukocyte activation, which may contribute to the pathogenesis of PPH.

Resveratrol (RESV) is a polyphenolic compound existed in native plants such as grape, fleeceflower root, and peanut, etc. The aim of this study was to investigate the effects in vitro of RESV on adenosine diphosphate (ADP)-induced platelet aggregation, platelet membrane-bound fibrinogen (PFig) its mechanism of action. The effects of RESV and phospholipase Cbeta inhibitor (U73122) on ADP-induced healthy human volunteers platelet aggregation, PFig, and the expression of phospho-phospholipase Cbeta3 (P-PLCbeta3) and total-phospholipase Cbeta3 (T-PLCbeta3) were studied with platelet aggregometer, flow cytometry and Western blotting, respectively. Compared with control group, RESV at 25, 50 and 100 micromol x L(-1) inhibited ADP-induced platelet aggregation and PFig in a dose dependent manner, and RESV at 25 micromol x L(-1) obviously reduced expression of P-PLCbeta3 and ratio of P-PLCbeta3 to T-PLCbeta3 in platelet of healthy human volunteers. Furthermore, RESV and U73122 had additive effect in inhibiting platelet aggregation and PFig. All these suggested that RESV inhibited platelet aggregation and PFig induced by ADP partly through decreasing the activity of PLCbeta of platelets, and that RESV had definite effect of antiplatelet and might be developed as a novel antithrombotic agent.