Phase noise suppression technique based on an improved reference interferometer scheme.

The reference interferometer scheme is an effective noise reduction method, but the optical path length difference (OPD) of the two interferometers must be strictly equal, which limits its application in practical environments. In this paper, an improved reference interferometer demodulation technique without strictly equal OPDs is proposed to suppress phase noise. By introducing a reference interferometer, the phase noise can be removed from the demodulation results. The combination of the differential self-multiplication algorithm and the fitted phase modulation depth calculation formula can evaluate the phase modulation depth of both interferometers in real time and simultaneously eliminate the nonlinear distortion caused by phase modulation depth drift and the effect of different OPDs on the reference interferometer scheme. The experimental results show that the technique can obtain highly stable and accurate demodulation results even if the OPDs of the two reference interferometers are different. The phase modulation depth calculation error is less than 0.57%, the maximum phase noise reduction is 15 dB, the average reduction is 9 dB, the minimum total harmonic distortion is 0.17%, and the SINAD reaches 35.90 dB.

Evaluation of the learning curve for transurethral plasmakinetic enucleation and resection of prostate using a mentor-based approach

ABSTRACT Objective To analyze the mentor-based learning curve of one single surgeon with transurethral plasmakinetic enucleation and resection of prostate (PKERP) prospectively. Materials and Methods Ninety consecutive PKERP operations performed by one resident under the supervision of an experienced endourologist were studied. Operations were analyzed in cohorts of 10 cases to determine when a plateau was reached for the variables such as operation efficiency, enucleation efficiency and frequency of mentor advice (FMA). Patient demographic variables, perioperative data, complications and 12-month follow-up data were analyzed and compared with the results of a senior urologist. Results The mean operative efficiency and enucleation efficiency increased from a mean of 0.49±0.09g/min and 1.11±0.28g/min for the first 10 procedures to a mean of 0.63±0.08g/min and 1.62±0.36g/min for case numbers 31-40 (p=0.003 and p=0.002). The mean value of FMA decreased from a mean of 6.7±1.5 for the first 10 procedures to a mean of 2.8±1.2 for case numbers 31-40 (p<0.01). The senior urologist had a mean operative efficiency and enucleation efficiency equivalent to those of the senior resident after 40 cases. There was significant improvement in 3, 6 and 12 month’s parameter compared with preoperative values (p<0.001). Conclusions PKERP can be performed safely and efficiently even during the initial learning curve of the surgeon when closely mentored. Further well-designed trials with several surgeons are needed to confirm the results.

Evaluation of the Learning Curve for Transurethral Plasmakinetic Enucleation and Resection of Prostate Using a Mentor-based Approach.

OBJECTIVE: To analyze the mentor-based learning curve of one single surgeon with transurethral plasmakinetic enucleation and resection of prostate (PKERP) prospectively. MATERIALS AND METHODS: Ninety consecutive PKERP operations performed by one resident under the supervision of an experienced endourologist were studied. Operations were analyzed in cohorts of 10 cases to determine when a plateau was reached for the variables such as operation efficiency, enucleation efficiency and frequency of mentor advice (FMA). Patient demographic variables, perioperative data, complications and 12-month follow-up data were analyzed and compared with the results of a senior urologist. RESULTS: The mean operative efficiency and enucleation efficiency increased from a mean of 0.49±0.09g/min and 1.11±0.28g/min for the first 10 procedures to a mean of 0.63±0.08g/min and 1.62±0.36g/min for case numbers 31-40 (p=0.003 and p=0.002). The mean value of FMA decreased from a mean of 6.7±1.5 for the first 10 procedures to a mean of 2.8±1.2 for case numbers 31-40 (p<0.01). The senior urologist had a mean operative efficiency and enucleation efficiency equivalent to those of the senior resident after 40 cases. There was significant improvement in 3, 6 and 12 month's parameter compared with preoperative values (p<0.001). CONCLUSIONS: PKERP can be performed safely and efficiently even during the initial learning curve of the surgeon when closely mentored. Further well-designed trials with several surgeons are needed to confirm the results.

Extraperitoneal versus transperitoneal laparoscopic radical cystectomy for selected elderly bladder cancer patients: a single center experience.

OBJECTIVE: This study reports the initial experience of extraperitoneal laparoscopic radical cystectomy (ELRC) and compared with transperitoneal laparoscopic radical cystectomy (TLRC) in the treatment of selected elderly bladder cancer patients. PATIENTS AND METHODS: A total of forty male bladder cancer patients who underwent ELRC (n=19) or TLRC (n=21) with ureterocutaneostomy were investigated. Demographic parameters, perioperative variables, oncological outcomes and follow-up data were retrospectively analyzed. RESULTS: A significantly shorter time to exsufflation (1.5±0.7 vs 2.1±1.1 d; p=0.026) and liquid intake (1.8±0.9 vs 2.8±1.9 d; p=0.035) were observed in the ELRC group compared with the TLRC group. The incidence of postoperative ileus in the ELRC group was lower than the TLRC group (0 vs 9.5%). However, the difference had no statistical significance (p>0.05). The removed lymph node number in the ELRC group was significantly lower than the TLRC group (p<0.001). No significant differences were observed between the two groups in the overall and cancer-free survival rates (p>0.05). CONCLUSIONS: ELRC seems to be a safe and feasible surgical strategy for the selected elderly bladder cancer patients with ≤T2 disease. The surgical and oncological efficacy of the ELRC is similar to that of the TLRC, but with faster intestinal function recovery. Further studies with a large series including different urinary diversions are needed to confirm our results and to better evaluate the benefit of ELRC in bladder cancer patients.

Extraperitoneal versus transperitoneal laparoscopic radical cystectomy for selected elderly bladder cancer patients: a single center experience

ABSTRACT Objective: This study reports the initial experience of extraperitoneal laparoscopic radical cystectomy (ELRC) and compared with transperitoneal laparoscopic radical cystectomy (TLRC) in the treatment of selected elderly bladder cancer patients. Patients and Methods: A total of forty male bladder cancer patients who underwent ELRC (n=19) or TLRC (n=21) with ureterocutaneostomy were investigated. Demographic parameters, perioperative variables, oncological outcomes and follow-up data were retrospectively analyzed. Results: A significantly shorter time to exsufflation (1.5±0.7 vs 2.1±1.1 d; p=0.026) and liquid intake (1.8±0.9 vs 2.8±1.9 d; p=0.035) were observed in the ELRC group compared with the TLRC group. The incidence of postoperative ileus in the ELRC group was lower than the TLRC group (0 vs 9.5%). However, the difference had no statistical significance (p>0.05). The removed lymph node number in the ELRC group was significantly lower than the TLRC group (p<0.001). No significant differences were observed between the two groups in the overall and cancer-free survival rates (p>0.05). Conclusions: ELRC seems to be a safe and feasible surgical strategy for the selected elderly bladder cancer patients with ≤ T2 disease. The surgical and oncological efficacy of the ELRC is similar to that of the TLRC, but with faster intestinal function recovery. Further studies with a large series including different urinary diversions are needed to confirm our results and to better evaluate the benefit of ELRC in bladder cancer patients.

Retroperitoneal Laparoendoscopic Single-Incision Radical Nephrectomy Without Special Platforms: A Single-Center Initial Experience.

OBJECTIVES: To describe the initial experience of retroperitoneal laparoendoscopic single-incision radical nephrectomy (LESI-RN) without special platforms and use of conventional laparoscopic instruments and assess the safety and feasibility of LESI-RN. SUBJECTS AND METHODS: Twenty patients who underwent LESI-RN were enrolled in this study. A 5-cm arc skin incision was performed at the midpoint between the costal arch and iliac crest on the midaxillary line. Trocars of 10, 5, and 11 mm were placed at the middle, left end, and right end of the arc incision, respectively. Demographic parameters and perioperative data were retrospectively analyzed and compared with the patients who underwent conventional retroperitoneal laparoscopic radical nephrectomy (LRN). RESULTS: The LESI-RN patients had a significantly lower visual analogue scale (4.4 ± 1.9 versus 5.6 ± 1.4; P = .031) and analgesic requirement (18.5 ± 11.2 versus 28.6 ± 16.1; P = .026) compared with the conventional LRN group. The operation time in the LESI-RN group was longer than that in the conventional LRN group (P = .001). The two procedures were essentially similar in terms of the time to liquid intake and hospital stay after operation (P > .05). CONCLUSIONS: LESI-RN is a safe and feasible surgical strategy, which combines the common principles of using straight instruments and working triangulation in conventional LRN with advantages of cosmesis and minimal invasiveness in laparoendoscopic single-site surgery. The surgical and oncological efficacy of LESI-RN is similar to that of conventional LRN but with significantly improved control of postoperative pain and cosmetic results.

Thulium Laser Enucleation Versus Plasmakinetic Enucleation of the Prostate: A Randomized Trial of a Single Center.

PURPOSE: To compare the safety and efficacy of thulium laser enucleation of the prostate (ThuLEP) with plasmakinetic enucleation of the prostate (PKEP). METHODS: A total of 127 patients with benign prostatic hyperplasia (BPH) were randomized to either ThuLEP (n = 61) or PKEP (n = 66). All patients were assessed preoperatively and followed up at 3, 6, and 12 months postoperatively. Baseline characteristics of the patients, perioperative data, postoperative outcomes, and complications were recorded. RESULTS: The decrease in hemoglobin level and the catheter time were statistically significantly lower in the ThuLEP group compared with the PKEP group (0.80 ± 0.49 vs 0.99 ± 0.52, p = 0.037, and 1.85 ± 0.94 vs 2.28 ± 1.34, p = 0.042). There were no statistical differences in complications between the two groups (p > 0.05). There was a significant improvement in 3, 6, and 12 months' parameters compared with preoperative values (p < 0.001). Assessment at the 12-month follow-up showed no difference in urinary parameters between the two groups. CONCLUSIONS: ThuLEP and PKEP are both safe and efficient procedures for the treatment of patients with BPH. Compared with PKEP, ThuLEP provided less risk of hemorrhage and shorter catheter time, although the differences may be of little clinical relevance. Further well-designed trials with extended follow-up and larger sample size are needed to draw final conclusions about the efficacy of the two procedures.

The prevalence of benign prostatic hyperplasia in mainland China: evidence from epidemiological surveys.

The epidemiological characteristics of benign prostate hyperplasia (BPH) in mainland China are not completely understood. We performed this meta-analysis to assess the prevalence of BPH from 1989 through 2014. A total of 14 articles and 19 datasets were included. The pooled overall prevalence of BPH among men aged 40 years and older was 36.6% [95% CI, 32.3-44.8]. The occurrence rate of BPH in the age groups 40-49 years, 50-59 years, 60-69 years, 70-79 years and 80 years and older was 2.9%, 29.0%, 44.7%, 58.1% and 69.2%, respectively. The pooled occurrence rate of BPH was 41.5% [95% CI, 34.5-48.4] in urban areas and 38.6% [95% CI, 22.7-54.6] in rural areas; this difference in prevalence was not statistically significant [OR, 1.51; 95% CI, 0.97-2.36]. BPH is highly prevalent in mainland China, and its prevalence increased with age. The trend in the prevalence of BPH in mainland China was not steady; the prevalence map based on a geographic information system (GIS) showed an unequal geographic distribution. High-quality surveys on BPH with a larger sample size are needed throughout mainland China to confirm these findings.

[Carcinoma recurrence rates after laparoscopic nephroureterectomy in patients undergoing transurethral incision of the ureteral orifice and open excision of bladder cuff].

OBJECTIVE: To compare the oncologic efficacy of transurethral incision of the ureteral orifice and open excision of bladder cuff in retroperitoneal laparoscopic nephroureterectomy (LNU) for patients with upper tract urothelium carcinoma. METHODS: The hospital records of 86 patients with upper tract urothelium carcinoma who underwent laparoscopic nephroureterectomy were reviewed retrospectively. 53 of the 86 patients, 22 males and 31 females, aged (68.6+/-14.1), underwent transurethral incision of the ureteral orifice (TUIUO), and 33, 14 males and 19 females, aged (72.4+/-15.2), underwent open excision of bladder cuff. Electric cauterization of the ureteral orifice was performed prior to resection. Follow-up was conducted for 28 (3-47) months. RESULTS: In all the specimens in the TUIUO group scar at the ureter orifice caused by electric excision could be seen. Test to check the pressure of distal ureter in 25 specimens proved that the ureters were all sealed. The distal ureter end began to leak at the water pressure of 135 cm in 1 case, at the water pressure of 167 cm in 1 case, and at 175 cm in 2 cases, but no leaking was seen even at 197 cm H2O in the other cases. Recurrence of bladder tumor was seen in 13 of the 53 patients of the TUIUO group and in 8 of the 33 patients of the open excision of bladder cuff group. Local recurrence developed in one case with the tumor at stage pT4N0M0 8 months after operation. CONCLUSION: Electric cauterization of the ureteral orifice prior to resection effectively ensures the leakproofness of the distal ureter end during LNU. As compared with open excision of bladder cuff, TUIUO does not increase the rate of neoplasm recurrence.

Glycocalyx damage estimated using colloidal iron staining.

Anionic constituents in the peritubular capillary basement membranes and the glomerular endothelial cells have been demonstrated to function as a size- and charge-selective barrier. Cationic colloidal iron staining of human biopsy specimens revealed a glycocalyx on the surface of the glomerular basement membrane (GBM), peritubular capillary (PTC) endothelial cells, and brush border of the tubular epithelial cells of normal kidney. However, the glycocalyx was abolished in the PTC wall of C4d-positive acute humoral rejected kidney, and in the GBM as well as the PTC wall of a chronic, allograft, nephropathy kidney. In addition, cyclosporine eliminated the glycocalyx in the PTC wall, while treatment with heparin inhibited the elimination of the PTC glycocalyx. In conclusion, the glycocalyx on the surface of the GBM and PTC is an important component in the endothelial cell barrier.

[Relationship between genetic polymorphism of NAT2 and susceptibility to urinary bladder cancer].

OBJECTIVE: To study the relationship between genetic polymorphism of NAT2 and susceptibility to bladder cancer. METHODS: NAT2 genotypes were determined by PCR-RFLP method in 69 patients with bladder transitional cell carcinoma and 88 healthy controls. RESULTS: The frequency of NAT2 slow genotypes was 26.1% (18/69) in patients compared with 14.8% (13/88) in controls (P < 0.05). Bladder cancer risk in patients with NAT2 slow genotypes was 2 fold as high as that in patients with NAT2 rapid genotypes. When NAT2 rapid genotypes/non-smoker were used as reference, bladder cancer risk increased to 5.8-fold (P < 0.05). Among the smokers with PY higher than 10, the patients showed a higher frequency of NAT2 slow genotype than controls (P < 0.05). It was also shown that the patients with slow NAT2 genotypes were more likely to have high grade tumor (P < 0.05) and advanced stage tumor (P < 0.01). CONCLUSION: The results suggest that NAT2 genetic polymorphism is associated with bladder cancer susceptibility. People with NAT2 slow genotype have higher bladder cancer risk.

[Application of complexity sequence in sleep staging based on sleep EEG data].

In this paper an approach of time-window complexity sequence is applied to sleep EEG analysis. This approach can reduce the loss of state information due to the nonstationarity of EEG signal and the unevenness of state space, and can overcome certain limitations of the complexity itself to some extent. It will help to extract the state features of EEG in different sleep stages. In addition, we preprocess EEG by adopting ICA and wavelet transform (WT). The results show that some physiological artifact in EEG can be eliminated effectively by these methods, and the sleep staging based on sleep EEG data will be more exact.