[Complications of transperineal template-guided prostate mapping biopsy].

Objective: To assess the complications of transperineal template-guided prostate mapping biopsy (TTMB). Methods: Between May 2017 and March 2018, 142 consecutive patients with prior negative transrectal biopsy results and persistently elevated prostate-specific antigen (PSA) were divided into the observation group and the control group randomly. The observation group underwent TTMB and the control group underwent transperineal template-guided prostate saturation biopsy (TTSB). Bleeding, infection, urinary function were recorded after prostate biopsy. Erectile function (ED) was measured at baseline, 1 month, 3 months and 6 months after prostate biopsy using the International Index of Erectile Function (IIEF-5). Results: A mean of 59 cores (from 33 to 116 cores) were obtained in TTMB, and a mean of 23 cores (from 11 to 44 cores) were obtained in TTSB. The positive rate was 50.0% (30/60) in TTMB, and 32.9% (27/82) in TTSB, and there were significant differences between two groups (P<0.05). The incidence of severe hematuria and urinary retention was 8.3% (5/60) and 11.7% (7/60) respectively in TTMB, while 1.2% (1/60) and 11.7% (7/60) respectively in TTSB. There were significant differences between two groups (P<0.05). But there were no significant differences between two groups in the incidence of mild, moderate and total hematuria, hematospermia, perineal hematoma, infection (P>0.05). Rectal bleeding was not observed. In TTMB group, the IIEF-5 scores at baseline, 1 month, 3 months and 6 months were (19.1±4.5), (17.4±4.8), (18.6±4.5), (19.0±4.0), respectively. In TTSB group, the IIEF-5 scores at baseline, 1 month, 3 months and 6 months were (19.7±4.3), (18.2±4.5), (19.1±4.1), (19.6±4.2), respectively. There were significant differences between baseline and 1 month after prostate biopsy in two groups (P<0.05), but there were no significant differences of IIEF-5 score between the two groups (P>0.05). Conclusions: TTMB can improve the positive rate for patients with prior negative transrectal biopsy results and persistently elevated PSA. TTMB has low complication rates, and most side-effects are self-limited. Compared with TTSB, the incidence of urinary retention and severe hematuria increases, but they can be recovered after clinical intervention. ED is transient, and affected for 1 month after the biopsy, but it will be recovered to the baseline after 3 to 6 months. Therefore, TTMB is a safe and reliable procedure.

Understanding of metal-insulator transition in VO2 based on experimental and theoretical investigations of magnetic features.

The metal-insulator transition temperature Tc in VO2 is experimentally shown to be almost the same as a magnetic transition temperature Tm characterized by an abrupt decrease in susceptibility, suggesting the evidence of the same underlying origin for both transitions. The measurement of susceptibility shows that it weakly increases on cooling for temperature range of T > Tm, sharply decreases near Tm and then unusually increases on further cooling. A theoretical approach for such unusual observations in susceptibility near Tm or below is performed by modeling electrons from each two adjacent V4+ ions distributed along V-chains as a two-electron system, which indicates that the spin exchange between electrons could cause a level splitting into a singlet (S = 0) level of lower energy and a triplet (S = 1) level of higher energy. The observed abrupt decrease in susceptibility near Tm is explained to be due to that the sample enters the singlet state in which two electrons from adjacent V4+ ions are paired into dimers in spin antiparallel. By considering paramagnetic contribution of unpaired electrons created by the thermal activation from singlet to triplet levels, an expression for susceptibility is proposed to quantitatively explain the unusual temperature-dependent susceptibility observed at low temperatures. Based on the approach to magnetic features, the observed metal-insulator transition is explained to be due to a transition from high-temperature Pauli paramagnetic metallic state of V4+ions to low-temperature dimerized state of strong electronic localization.

[Effect of prostate volume on the peripheral nerve block anesthesia in prostate biopsy].

OBJECTIVE: To evaluate the anesthetic efficacy of periprostatic nerve block in transrectal ultrasound(TRUS) guided biopsy on different prostate volume. METHODS: A total of 568 patients received prostate biopsy in Department of Urology, Subei People's Hospital from May 2013 to September 2015 were retrospectively studied. All patients were divided into local anesthesia group and nerve block group according to different way of anesthesia. Then each group was divided into four subgroups(20-40 ml, >40-60 ml, >60-100 ml and >100 ml subgroups) according to different prostate volume range. After being anaesthetized successfully, patients in two groups underwent prostate biopsy, visual analogue scale(VAS) scores, visual numeric scale(VNS)scores and complications were recorded and analyzed. At inter-group and intra-group in local anesthesia group and nerve block group, Mann-Whitney U test of non-parametric analysis and single factor variance analysis were used to compare the VAS scores and the VNS scores respectively, and chi-square test was used to compare the rates of complication. RESULTS: The VAS scores of four subgroups: local anesthesia group: 1.9±0.9, 2.8±1.5, 3.8±2.3 and 5.3±2.5; nerve block group: 1.5±0.7, 2.0±0.8, 2.9±1.7 and 4.2±2.0. The VNS scores: local anesthesia group: 3.4±0.6, 2.9±0.6, 2.7±0.5 and 1.6±0.7; nerve block group: 3.7±0.5, 3.3±0.4, 3.0±0.8 and 2.0±0.7. The VAS scores and the VNS scores had significant differences (Z=-3.637-98.253, all P<0.05) at inter-group or intra-group level. For the complication rates of operation, hematuria, blood, urinary retention were significant differences (F=1.347-15.402, all P<0.05) at intra-group level. But there were no significant differences at inter-group level(P>0.05). CONCLUSION: Compared with local anesthesia, ultrasound guided prostate peripheral nerve block anesthesia has great analgesic effect and high safety, but for patients with a large prostate volumethe analgesic effect is inefficiency.