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1.
Biomed Res Int ; 2019: 4572130, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467891

RESUMO

Purpose: Acute kidney injury (AKI) is a major and severe complication following donation-after-circulatory-death (DCD) liver transplantation (LT) and is associated with increased postoperative morbidity and mortality. However, the risk factors and the prognosis factors of AKI still need to be further explored, and the relativity of intraoperative hepatic blood inflow (HBI) and AKI following LT has not been discussed yet. The purpose of this study was to investigate the correlation between HBI and AKI and to construct a prediction model of early acute kidney injury (EAKI) following DCD LT with the combination of HBI and other clinical parameters. Methods: Clinical data of 132 patients who underwent DCD liver transplantation at the first hospital of China Medical University from April 2005 to March 2017 were analyzed. Data of 105 patients (the first ten years of patients) were used to develop the prediction model. Then we assessed the clinical usefulness of the prediction models in the validation cohort (27 patients). EAKI according to Kidney Disease Improving Global Outcomes (KDIGO) criteria based on serum creatinine increase during 7-day of postoperative follow-up. Results: After Least Absolute Shrinkage and Selection Operator (LASSO) regression and simplification, a simplified prediction model consisting of the Child-Turcotte-Pugh (CTP) score (p=0.033), anhepatic phase (p=0.014), packed red blood cell (pRBC) transfusion (p=0.027), and the HBI indexed by height (HBI/h) (p=0.002) was established. The C-indexes of the model in the development and validation cohort were 0.823 [95% CI, 0.738-0.908] and 0.921 [95% CI, 0.816-1.000], respectively. Conclusions: In this study, we demonstrated the utility of HBI/h as a predictor for EAKI following DCD LT, as well as the clinical usefulness of the prediction model through the combination of the CTP score, anhepatic phase, pRBC transfusion and HBI/h.

2.
EBioMedicine ; 45: 231-250, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31202812

RESUMO

BACKGROUND: Epidemiological evidence of over 9000 people suggests that daily intake of vinegar whose principal bioactive component is acetic acid is associated with a reduced risk of nephrolithiasis. The underlying mechanism, however, remains largely unknown. METHODS: We examined the in vitro and in vivo anti-nephrolithiasis effects of vinegar and acetate. A randomized study was performed to confirm the effects of vinegar in humans. FINDINGS: We found individuals with daily consumption of vinegar compared to those without have a higher citrate and a lower calcium excretion in urine, two critical molecules for calcium oxalate (CaOx) kidney stone in humans. We observed that oral administration of vinegar or 5% acetate increased citrate and reduced calcium in urinary excretion, and finally suppressed renal CaOx crystal formation in a rat model. Mechanism dissection suggested that acetate enhanced acetylation of Histone H3 in renal tubular cells and promoted expression of microRNAs-130a-3p, -148b-3p and -374b-5p by increasing H3K9, H3K27 acetylation at their promoter regions. These miRNAs can suppress the expression of Nadc1 and Cldn14, thus enhancing urinary citrate excretion and reducing urinary calcium excretion. Significantly these mechanistic findings were confirmed in human kidney tissues, suggesting similar mechanistic relationships exist in humans. Results from a pilot clinical study indicated that daily intake of vinegar reduced stone recurrence, increased citrate and reduced calcium in urinary excretion in CaOx stone formers without adverse side effects. INTERPRETATION: Vinegar prevents renal CaOx crystal formation through influencing urinary citrate and calcium excretion via epigenetic regulations. Vinegar consumption is a promising strategy to prevent CaOx nephrolithiasis occurrence and recurrence. FUND: National Natural Science Foundations of China and National Natural Science Foundation of Guangdong Province.

3.
Int. braz. j. urol ; 45(3): 617-620, May-June 2019.
Artigo em Inglês | LILACS-Express | ID: biblio-1012325

RESUMO

ABSTRACT Objective: Pyeloplasty is considered the gold standard treatment for ureteropelvic junction obstruction (UPJO). However, the failure rate of pyeloplasty is as high as 10% and repeat pyeloplasty is more difficult. This study aimed to evaluate the efficacy of balloon dilatation for failed pyeloplasty in children. Materials and Methods: Between 2011 and 2017, 15 patients, aged 6 months to 14 years, were treated with balloon dilation for restenosis of UPJO after a failed pyeloplasty. Ultrasound and intravenous urography were used to evaluate the primary outcome. Success was defined as the relief of symptoms and improvement of hydronephrosis, which was identified by ultrasound at the last follow-up. Results: All patients successfully completed the operation, 13 patients by retrograde approach and 2 patients by antegrade approach. Thirteen patients were followed for a median of 15 (4 to 57) months and 2 patients were lost to follow-up. Resolution of the hydronephrosis was observed in 5 cases. The anteroposterior diameter (APD) of the pelvis decreased by an average of 12.4 ± 14.4mm. Eight patients needed another surgery. The average postoperative hospital stay was 1.78 ± 1.4 days. Two patients experienced fever after balloon dilation. No other complications were found. Conclusions: Balloon dilatation surgery is safe for children, but it is not recommended for failed pyeloplasty in that group of patients, owing to the low success rate.

4.
Opt Lett ; 44(8): 1944-1947, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30985781

RESUMO

We report on the demonstration of a 386 nm light emission and detection dual-functioning device based on nonpolar a-plane n-ZnO/i-ZnO/p-Al0.1Ga0.9N heterojunction under both forward and reverse bias. The electroluminescence intensity under reverse bias is significantly stronger than that under forward bias, facilitated by carrier tunneling when the valence band of p-AlGaN aligns with the conduction band of i-ZnO under reverse bias. Also amid reverse bias, the photodetection was observed and applied in a duplex optical communication device. Optical polarization of the light emission is studied for potential polarization-sensitive device applications. The proposed device provides an important pathway for the multifunctional devices operating in a UV spectrum.

5.
Endocr Res ; 44(3): 103-109, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30773948

RESUMO

Aims: To investigate the association between body mass index (BMI) and all-cause mortality in patients with type 2 diabetes mellitus (T2DM) and to determine any sex-specific differences in this association. Methods: We retrospectively enrolled patients with T2DM and investigated the annual death data for seven years starting from 2010. All-cause mortality was calculated using Life Tables analysis. Multivariate Cox proportional hazards analysis was performed to identify the association between BMI and mortality. Results: During a mean survey period of 7.33 ± 1.42 years (X± SD), 996 of the 17259 patients enrolled died, resulting in an all-cause mortality rate of 5.77%, with no significant difference between women and men (6.04% vs. 5.56%; x2 = 1.766, P = 0.184). The top three causes of death were ischemic heart disease, cerebrovascular disease, and chronic kidney failure. A total of 87, 266, 332, and 311 patients with a BMI of <18.5, 18.5-23.99, 24.0-27.99, and ≥28.0 kg/m2, respectively, died, with the corresponding mortality rate calculated at 15.45%, 3.30%, 5.80%, and 10.70%, respectively. The BMI value associated with the highest all-cause mortality was <18.5 kg/m2, but this association was only significant in women aged <50 years (HR: 3.12; 95% CI, 1.62-4.34; P < 0.001). Conclusions: In patients with T2DM, a low BMI in women aged <50 years predicted high all-cause mortality.

6.
Int Braz J Urol ; 45(3): 617-620, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30676306

RESUMO

OBJECTIVE: Pyeloplasty is considered the gold standard treatment for ureteropelvic junction obstruction (UPJO). However, the failure rate of pyeloplasty is as high as 10% and repeat pyeloplasty is more difficult. This study aimed to evaluate the efficacy of balloon dilatation for failed pyeloplasty in children. MATERIALS AND METHODS: Between 2011 and 2017, 15 patients, aged 6 months to 14 years, were treated with balloon dilation for restenosis of UPJO after a failed pyeloplasty. Ultrasound and intravenous urography were used to evaluate the primary outcome. Success was defined as the relief of symptoms and improvement of hydronephrosis, which was identified by ultrasound at the last follow-up. RESULTS: All patients successfully completed the operation, 13 patients by retrograde approach and 2 patients by antegrade approach. Thirteen patients were followed for a median of 15 (4 to 57) months and 2 patients were lost to follow-up. Resolution of the hydronephrosis was observed in 5 cases. The anteroposterior diameter (APD) of the pelvis decreased by an average of 12.4 ± 14.4mm. Eight patients needed another surgery. The average postoperative hospital stay was 1.78 ± 1.4 days. Two patients experienced fever after balloon dilation. No other complications were found. CONCLUSIONS: Balloon dilatation surgery is safe for children, but it is not recommended for failed pyeloplasty in that group of patients, owing to the low success rate.


Assuntos
Pelve Renal/cirurgia , Obstrução Ureteral/cirurgia , Cateterismo Urinário/métodos , Procedimentos Cirúrgicos Urológicos/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Hidronefrose/cirurgia , Lactente , Pelve Renal/diagnóstico por imagem , Masculino , Reprodutibilidade dos Testes , Resultado do Tratamento , Ultrassonografia/métodos , Obstrução Ureteral/diagnóstico por imagem , Cateterismo Urinário/instrumentação , Urografia/métodos , Procedimentos Cirúrgicos Urológicos/instrumentação
7.
PLoS One ; 13(10): e0206048, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30339676

RESUMO

OBJECTIVE: To compare the efficacy and safety of micropercutaneous nephrolithotomy (Microperc) and retrograde intrarenal surgery (RIRS) in treating renal stones using published literature. METHODS: A systematic literature review was performed on August 21, 2017, using PubMed, Embase, and Cochrane Library databases in accordance with the PRISMA guidelines. Summarized mean differences (MDs) or odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the differences in outcomes between Microperc and RIRS. RESULTS: A total of nine studies (7 in adult patients and 2 in pediatric patients) containing 842 patients (381 Microperc cases and 461 RIRS cases) with renal stones were included in this analysis. Among the adult patients, Microperc was associated with higher stone-free rate(SFR)(OR: 1.6; 95% CI, 1.03 to 2.48), significantly longer hospital stays (MD: 0.66 day; 95% CI, 0.17 to 1.15), longer fluoroscopy time (MD: 78.12 s; 95% CI, 66.08 to 90.15), and larger decreases in hemoglobin (MD: 0.59 g/dl; 95% CI, 0.16 to 1.02) than was RIRS. No significant differences were observed with respect to operative time, stone-free rate, complication rate or auxiliary procedures. CONCLUSIONS: Our results demonstrated that Microperc might be more effective in adult patients than RIRS will due to its higher SFR. However, longer hospital stays, longer fluoroscopy time and a larger decrease in hemoglobin should be considered cautiously.

8.
Int. braz. j. urol ; 44(5): 865-873, Sept.-Oct. 2018. tab, graf
Artigo em Inglês | LILACS-Express | ID: biblio-975633

RESUMO

Abstract Objective: To assess the relationship between 5α-reductase inhibitors (5ARIs) and the risk of male breast cancer (MBC). Material and Methods: We systematically searched Medline via PubMed, Embase and the Cochrane Library Central Register up to May 2017 to identify published articles related to 5ARIs and the risk of MBC. Results: Summary effect estimates were calculated by a random-effect model, and tests for multivariable-unadjusted pooled risk ratios (RR) and heterogeneity, as well as the sensitivity analyses were conducted to assess publication bias. All four studies were conducted in a quality assessment according to the Newcastle Ottawa Scale system. The strength of association between 5ARIs and the prevalence of MBC was evaluated by using summarized unadjusted pooled RR with a 95% confidence interval [CI]. Four studies involving 595.776 participants, mean age range from 60 to 73.2 years old, were included in a meta-analysis, which produced a summary unadjusted RR of the risk of MBC for the treatment of 5ARIs of 1.16 (95% CI 0.85-1.58, P=0.36) and the multivariable-adjusted RR is 1.03, (95% CI 0.75-1.41, p=0.86). There was no heterogeneity among included studies (I2=0%, P=0.49). Estimates of total effects were generally consistent with the sensitivity. Conclusion: We did not observe a positive association between the use of 5ARIs and MBC. The small number of breast cancer cases exposed to 5ARIs and the lack of an association in our study suggest that the development of breast cancer should not influence the prescribing of 5ARIs therapy.

9.
BJU Int ; 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-30253029

RESUMO

OBJECTIVES: To evaluate the long-term outcomes of patients undergoing observation of asymptomatic renal calculi and identify factors associated with stone-related events. PATIENTS AND METHODS: Patients with asymptomatic renal calculi electing active surveillance of their stones were retrospectively reviewed. Patients underwent annual ultrasonography and clinical visits with standardised questions regarding the development of symptoms or complications from calculi. Spontaneous stone passage, stone growth, development of stone-related symptoms, and requirement for intervention during follow-up were deemed as stone-related events. RESULTS: Between 2007 and 2017, 293 patients were reviewed to evaluate the natural history of asymptomatic renal calculi. The mean follow-up was 4.2 years. Overall incidences of spontaneous passage, stone growth, development of stone-related symptoms, and requirement of intervention were 32.1%, 16.7%, 28.3% and 12.3%, respectively. Stones >5 mm and lower pole stones were significantly less likely to pass spontaneously. Patients with diabetes mellitus (DM), hyperuricaemia or non-lower calyceal stone were more likely to experience stone growth. Stones >5 mm or non-lower pole stones were more likely to become symptomatic. Significant predictors of surgical intervention were stone size (>5 mm) and patients' age (>60 years). Primary therapy was extracorporeal shockwave lithotripsy in 33 patients and flexible ureteroscopy in three. CONCLUSION: The natural history of asymptomatic renal stones rarely requires intervention, although they do have a slightly higher rate of symptomatic events and growth over the intermediate term. In particular, patients with stones >5 mm, DM, hyperuricaemia, or non-lower calyceal stones are at higher risk of developing stone-related events, and should therefore be recommended for regular follow-up.

10.
ACS Appl Mater Interfaces ; 10(23): 20085-20094, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29772174

RESUMO

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 vs 8.09 W/mK are measured for samples with tilt angles of 10° versus 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

11.
Transplantation ; 102(11): 1850-1856, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29787521

RESUMO

BACKGROUND: Islet grafts are transplanted into the liver via a portal vein in 90% of the clinical islet transplantations. However, the portal vein is far from being the ideal infusion site due to its unique drawbacks. These issues necessitated the exploration of an alternatively optimized site for clinical islet transplantation. With the widespread clinical application of percutaneous transhepatic puncture technique, we envisioned the possibility of islet transplantation into the hepatic sinus tract (HST). METHODS: The HST was created by temporarily placing a medically approved material into the hepatic parenchyma of C57BL/6 mice. The syngeneic islets were transplanted into the HST, after which, the nonfasting blood glucose, intraperitoneal glucose tolerance, and morphology were evaluated. RESULTS: A collagen-lined HST was formed by the 28-day implantation of a cylindrical nylon rod. Transplantation of ~300 syngeneic islets into the HST routinely reversed the hyperglycemia of the recipient mice and maintained normoglycemia for longer than 100 days until the graft was removed. The islet grafts within the HST stained positively for insulin, glucagon, and abundant microvessels and achieved comparable results to the islet grafts under the kidney capsule with respect to glycemic control and glucose tolerance. CONCLUSIONS: These results suggested that an HST can be constructed for islet transplantation by temporarily placing a nylon material in the liver parenchyma. The HST is a promising site for clinical islet transplantation, thereby providing a satisfactory environment for the survival and metabolic function of islet grafts.

12.
Int Braz J Urol ; 44(5): 865-873, 2018 Sep-Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29697934

RESUMO

OBJECTIVE: To assess the relationship between 5α-reductase inhibitors (5ARIs) and the risk of male breast cancer (MBC). MATERIAL AND METHODS: We systematically searched Medline via PubMed, Embase and the Cochrane Library Central Register up to May 2017 to identify published articles related to 5ARIs and the risk of MBC. RESULTS: Summary effect estimates were calculated by a random-effect model, and tests for multivariable-unadjusted pooled risk ratios (RR) and heterogeneity, as well as the sensitivity analyses were conducted to assess publication bias. All four studies were conducted in a quality assessment according to the Newcastle Ottawa Scale system. The strength of association between 5ARIs and the prevalence of MBC was evaluated by using summarized unadjusted pooled RR with a 95% confidence interval [CI]. Four studies involving 595.776 participants, mean age range from 60 to 73.2 years old, were included in a meta-analysis, which produced a summary unadjusted RR of the risk of MBC for the treatment of 5ARIs of 1.16 (95% CI 0.85-1.58, P=0.36) and the multivariable-adjusted RR is 1.03, (95% CI 0.75-1.41, p=0.86). There was no heterogeneity among included studies (I2=0%, P=0.49). Estimates of total effects were generally consistent with the sensitivity. CONCLUSION: We did not observe a positive association between the use of 5ARIs and MBC. The small number of breast cancer cases exposed to 5ARIs and the lack of na association in our study suggest that the development of breast cancer should not influence the prescribing of 5ARIs therapy.

13.
BMC Nephrol ; 19(1): 56, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523086

RESUMO

BACKGROUND: Renal transplant is the preferred treatment option for these patients with end-stage renal disease. Transplant renal artery stenosis (TRAS) is one of the most common and serious vascular complications after renal transplantation, and most of the TRAS occurred in the anastomosis. The complication must be diagnosed and treated timely, otherwise the function of transplanted kidney may be losed. CASE PRESENTATION: A 46-year-old male with end-stage renal disease of unknown cause received a cadaveric renal transplant one year ago. Although three antihypertensive medications were administrated, his blood pressure gradually increased to 190/120 mmHg 3 weeks posttransplantation. Also the level of creatinine increased to 194 µmol/L.Color Doppler ultrasonography indicated a decreased resistance index (RI) in intrarenal arteries and increased blood flow of the transplant renal artery, therefore, a vascular complication of TRAS was suspected. Arteriography was performed and demonstrated TRAS caused by stretch of an artery branch, and the TRAS occurred in the distal site of the anastomosis instead of the anastomosis. Percutaneous transluminal bare stent implantation treatment was successfully performed. Satisfactory clinical efficacy with improvement in transplant renal function and renovascular hypertension was achieved after the interventional treatment. CONCLUSION: To our knowledge this is the first reported case of TRAS caused by stretch of an artery branch. When refractory hypertension and allograft dysfunction are presented posttransplantation, TRAS should be suspected. Color Doppler ultrasonography as a non-invasive examination may provide some valuable information, three-dimention CT can be useful for further diagnosis, but is seldom necessary. Arteriography provides the definitive diagnosis of TRAS. Percutaneous transluminal stent implantation treatment of TRAS has high success rate with minimal invasion and complications. When an artery branch situated on the stenosis, a bare stent rather than covered stent is the preferred choice.

14.
PLoS One ; 13(3): e0194606, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29566037

RESUMO

OBJECTIVES: A number of researchers have reported that vasectomy is a risk factor for testicular cancer. However, this conclusion is inconsistent with a number of other published articles. Hence, we conducted this meta-analysis to assess whether vasectomy increases the risk of testicular cancer. MATERIALS AND METHODS: We identified all related studies by searching the PubMed, Embase, and Cochrane Library database from January 01, 1980 to June 01, 2017. The Newcastle-Ottawa Scale (NOS) checklist was used to assess all included non-randomized studies. Summarized odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the difference in outcomes between case and control groups. Subgroup analyses were performed according to the study design and country. RESULTS: A total of eight studies (2176 testicular cancer patients) were included in this systematic review and meta-analysis. Six articles were case-control studies, and two were cohort studies. The pooled estimate of the OR was 1.10 (95% CI: 0.93-1.30) based on the eight studies in a fixed effects model. Two subgroup analyses were performed according to the study design and country. The results were consistent with the overall findings. Publication bias was detected by Begg's test and Egger's test and p values > 0.05, respectively. CONCLUSIONS: Our meta-analysis suggested that there was no association between vasectomy and the development of testicular cancer. More high-quality studies are warranted to further explore the association between vasectomy and risk of testicular cancer.


Assuntos
Neoplasias Testiculares/epidemiologia , Vasectomia/estatística & dados numéricos , Estudos de Casos e Controles , Estudos de Coortes , Humanos , Masculino , Neoplasias Embrionárias de Células Germinativas/epidemiologia , Neoplasias Embrionárias de Células Germinativas/etiologia , Fatores de Risco , Neoplasias Testiculares/etiologia , Vasectomia/efeitos adversos
16.
Opt Express ; 25(24): A1053-A1056, 2017 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-29220983

RESUMO

In the original manuscript, the maximum short-circuit current in Fig. 2 and the description of angular stability for polarization in Fig. 6 are found incorrect owing to negligence. The incorrect maximum integrated absorption also led to errors appeared in Fig. 3 and Fig. 4(d), in which the mistake value was used to plot. In this erratum, all of those mistakes have been corrected. Moreover, both higher Fourier expansion order and the resolution of frequency are adopted in the recalculation to make sure the updated results to be reliable. The updated data presented still support the main conclusions drawn in the previous manuscript.

17.
Int J Endocrinol ; 2017: 3709306, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29138633

RESUMO

Objective: This study aimed to determine the use of fecal elastase in evaluating the effect of simultaneous pancreas-kidney transplantation with enteric drainage on the pancreatic exocrine function of diabetic patients with uremia. Methods: A total of 19 patients with simultaneous pancreas-kidney transplantation (SPK) with enteric drainage, 31 diabetic patients with uremia (chronic renal failure (CRF)), 22 diabetic patients with uremia who underwent renal transplantation (RT), and 20 normal individuals (CON) were included in the study. Pancreatic exocrine insufficiency was determined using fecal elastase. Results. The fecal pancreatic elastase level in SPK patients with enteric drainage was 479 µg/g, which was significantly higher than 229 µg/g in CRF patients and 197 µg/g in RT patients. Using 200 µg/g as the established threshold, a reduced fecal pancreatic elastase level was found in 14/31 of CRF patients, 12/22 of RT patients, 1/19 of SPK patients with enteric drainage, and 1/20 of CON patients. The correlation analysis revealed a significant association between fecal elastase and glycosylated hemoglobin. Conclusions: The present study indicated that SPK with enteric drainage improves pancreatic endocrine and exocrine functions. Fecal elastase may be a clinically relevant means to determine the therapeutic effects.

18.
Opt Express ; 25(19): 23267-23274, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-29041627

RESUMO

A demonstration of ultraviolet-B (UVB) communication link is implemented utilizing quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM). The demonstration is based on a 294-nm UVB-light-emitting-diode (UVB-LED) with a full-width at half-maximum (FWHM) of 9 nm and light output power of 190 µW, at 7 V, with a special silica gel lens on top of it. A -3-dB bandwidth of 29 MHz was measured and a high-speed near-solar-blind communication link with a data rate of 71 Mbit/s was achieved using 8-QAM-OFDM at perfect alignment. 23.6 Mbit/s using 2-QAM-OFDM when the angle subtended by the pointing directions of the UVB-LED and photodetector (PD) is 12 degrees, thus establishing a diffuse-line-of-sight (LOS) link. The measured bit-error rate (BER) of 2.8 ×10-4 and 2.4 ×10-4, respectively, are well below the forward error correction (FEC) criterion of 3.8 ×10-3. The demonstrated high data-rate OFDM-based UVB communication link paves the way for realizing high-speed non-line-of-sight free-space optical communications.

19.
Opt Express ; 25(20): A922-A931, 2017 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-29041302

RESUMO

By emulating the phyllotaxis structure of natural plants, which has an efficient and stable light capture capability, a two-dimensional spiral grating is introduced on the surface of crystalline silicon solar cells to obtain both efficient and stable light absorption. Using the rigorous coupled wave analysis method, the absorption performance on structural parameter variations of spiral gratings is investigated firstly. Owing to diffraction resonance and excellent superficies antireflection, the integrated absorption of the optimal spiral grating cell is raised by about 77 percent compared with the conventional slab cell. Moreover, though a 15 percent deviation of structural parameters from the optimal spiral grating is applied, only a 5 percent decrease of the absorption is observed. This reveals that the performance of the proposed grating would tolerate large structural variations. Furthermore, the angular and polarization dependence on the absorption of the optimized cell is studied. For average polarizations, a small decrease of only 11 percent from the maximum absorption is observed within an incident angle ranging from -70 to 70 degrees. The results show promising application potentials of the biomimetic spiral grating in the solar cell.

20.
J Endourol ; 31(11): 1157-1163, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28895477

RESUMO

PURPOSE: The study sought to compare the procedural and clinical results of super-mini-percutaneous nephrolithotomy (SMP) with the use of first- and new-generation devices. METHODS: A prospective, comparative cohort study was carried out between February 2013 and January 2017. Patients who underwent either first- or new-generation SMP were eligible for the study. Inclusion criteria were adult patients with renal stone <4 cm, or in pediatric patients with renal stone <2.5 cm with a history of failed extracorporeal shockwave lithotripsy. The primary outcome of the present study was the operating time, which was calculated from the starting of percutaneous puncture to the wound closure. Secondary outcomes were the stone-free rate (SFR), blood loss (hemoglobin decrease), hospital stay, and postoperative complications. RESULTS: One hundred fifty-six consecutive patients who underwent SMP for treatment of renal stones were eligible for the study, with the first 85 patients undergoing SMP with the first-generation device, and the remaining 71 consecutive patients being treated with the new-generation SMP system. The two groups of patients had comparable demographic data, including age, BMI, stone size, Guy's score, stone location, comorbidities, grade of hydronephrosis, and history of urinary tract infection. The new-generation SMP had a shorter operation time (39.3 vs 50.5 min, p = 0.016) and shorter postoperative hospitalization time (2.1 vs 3.0 days, p < 0.001) than the first-generation SMP. No significant difference existed between the two groups for SFR, hemoglobin decrease, and tubeless rate. The overall operative complication rates using the Clavien-Dindo grading system were similar between the two cohorts of patients. CONCLUSION: The clinical outcomes of the new-generation SMP in patients with moderate-sized renal stone were comparable when compared with the first-generation SMP. New-generation SMP system using an irrigation/suction sheath improved intraoperative irrigation, a more efficient hydrodynamic mechanism for retrieval of fragments. This may account for the shorter operative time than the first-generation SMP system demonstrated in this study.


Assuntos
Cálculos Renais/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Nefrolitotomia Percutânea/instrumentação , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Miniaturização , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Nefrolitotomia Percutânea/métodos , Duração da Cirurgia , Complicações Pós-Operatórias , Estudos Prospectivos , Irrigação Terapêutica/instrumentação , Resultado do Tratamento
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