Yosuke Kawamura

Electrodeposition of Noble Metals into Ordered Macropores in p-Type Silicon

The electrodeposition of noble metals, i.e., platinum, palladium, and gold, into macroporous p-type silicon was examined. For platinum and palladium, the electrodeposition proceeded preferentially from the pore bottom to the opening when sodium chloride was used as a supporting electrolyte. When sodium sulfate was used as a supporting electrolyte, the electrodeposition mainly proceeded at pore openings, leading to plugging. For gold electrodeposition, a condition for achieving pore filling from the bottom was not found in either the NaCI or Na 2 SO 4 solutions. Pore depth was another key factor to achieve continuous filling by electrodeposition. As the depth of pores became deeper, the electrodeposition proceeded preferentially from the bottom. The effect of mass transfer in pores was also investigated by changing the concentration of metal ions and applied potential.

Photoassisted Control of Pt Electrodeposition on p-Type Si

A new method to control the size and distribution of electrodeposited metal on a semiconductor was investigated, using a system of Pt deposition on p-type Si. Pt is a noble metal, and electrodeposition is possible on p-type Si through hole injection to the valence band. When the Si surface is illuminated, an additional charge-transfer path becomes possible utilizing electrons photo-excited to the conduction band. The two pathways give different morphologies for the deposits. Fine and dispersed particles were electrodeposited under illumination, indicating the nucleation process was prevailing; in the dark, grown deposits were observed and the dominant process was crystal growth. We used the different deposition behavior to control the size and distribution of electrodeposits by the illumination-modulated method. Initial illumination gives nuclei of electrodeposits, and the adjustment of the duration can control the number of electrodeposits. The following electrolysis in the dark grows the deposits and can control the size. The method showed the possibility of controlling the size and distribution of Pt electrodeposits on p-type Si without changing applied potential.

Pyomayoma during pregnancy: A case report and review of the literature

Pyomyoma (suppurative leiomyoma) is a rare but serious complication of uterine leiomyomas. Although the management of leiomyomas during pregnancy is usually expectant, prompt surgical intervention is mandatory for pyomyoma. We present a case of pyomyoma with peritonitis that necessitated myomectomy at 21 weeks of gestation in a 28‐year‐old nullipara in which the pregnancy continued to successful delivery at 37 weeks of gestation. Perinatal and neonatal outcomes in pregnancies complicated with pyomyoma may be improved by prompt surgical intervention even in the early second trimester. A brief review of the literature regarding pyomyoma associated with pregnancy is also described.

Cervical clamp with ring forceps to prevent prolapse of an intrauterine balloon in the management of postpartum hemorrhage

An intrauterine balloon tamponade is a simple but highly effective method for the management of postpartum hemorrhage. However, treatment failure can occur due to prolapse of an intrauterine balloon into the vagina. We present two cases with a successful maneuver in maintaining the intrauterine placement of the balloon by clamping the cervix with two ring forceps in the management of postpartum hemorrhage. Although the balloon was initially expelled through a dilated cervix, a cervical clamp using ring forceps prevented displacement of the balloon, and the hemorrhage ceased. Clamping the cervix with two ring forceps to retain the balloon can be a simple and readily available approach to consider when an intrauterine balloon tamponade does not work due to its expulsion.

Treatment decision‐making for post‐partum hemorrhage using dynamic contrast‐enhanced computed tomography

Post‐partum hemorrhage (PPH) is the leading cause of maternal mortality. Identification of the precise bleeding site is generally important to control hemorrhage, but such an approach has not been fully established in the context of PPH. We postulated that visualization of bleeding sites could aid treatment decisions in the management of PPH.

Impaired Wnt5a signaling in extravillous trophoblasts: Relevance to poor placentation in early gestation and subsequent preeclampsia

BACKGROUND Defective decidual endovascular trophoblast invasion and subsequent impaired spiral artery remodeling is highly associated with the pathogenesis of preeclampsia (PE). Since there are scant and conflicting data regarding the function of Wnt5a signaling in extravillous trophoblasts (EVT), the aim of this study was to investigate whethere impaired Wnt5a signaling affects the invasive and tube forming capabilities of EVT. METHODS Expression levels of Wnt ligands were compared between first trimester chorionic villi of women who later developed PE and women with unaffected pregnancies using publicly available microarray data (GSE12767). Wnt5a expression was examined in placentas using quantitative RT-PCR, Western blot analysis and immunohistochemistry. The function of Wnt5a signaling in EVT was investigated in an immortalized first trimester EVT cell line, HTR-8/SVneo, using small-interfering RNAs, recombinant human Wnt5a (rhWnt5a), and inhibitors of JNK or PKC. RESULTS Microarray data analysis of the first trimester placentas showed that, among Wnt ligands, Wnt5a expression was significantly lower in women who later developed PE. The mRNA and protein expression levels of Wnt5a were significantly decreased in PE placentas compared with normal term placentas. Wnt5a knockdown significantly suppressed invasion and tube formation of HTR-8/SVneo cells, while the addition of rhWnt5a augmented the cell migration, invasion, and tube formation. Repression of Wnt5a/PKC signaling in HTR-8/SVneo cells inhibited cell invasion, but did not alter cell tube formation. In contrast, inhibition of Wnt5a/JNK signaling attenuated rhWnt5a-induced invasion and tube formation capabilities. CONCLUSIONS These findings suggest that impaired Wnt5a signaling is associated with poor placentation and subsequent PE.

An attempt to simplify total laparoscopic hysterectomy procedures at our hospital

Objective: We are currently testing a simplified and safe laparoscopic hysterectomy procedure in our clinical practice that is technically similar to laparotomy. The present study aimed to evaluate the feasibility of this modified total laparoscopic hysterectomy (TLH) method, which uses the RUMI II Colpotomiser System and without requiring separation of the ureter and uterine artery for laparoscopic surgeons under training. Methods: During the procedure, uterine vessels and ureters are not skeletonized, the vaginal vault is identified using a colpotomy cup, and retrograde dissection is performed from the anterior vaginal wall. We used statistical analysis to evaluate operative time, parity, body mass index (BMI), blood loss, and surgery-related complications by Students t-test. Results: We have performed 11 TLH procedures applying the above method, excluding cases of severe adhesion, since 2016. Compared with the traditional TLH method, average operating time was significantly shorter using the new method. There was no significant difference between the two groups with regards to parity, BMI, or blood loss. No complications have occurred postoperatively since 2016; whereas, one vesicovaginal fistula occurred in the 18 TLH performed before 2016. Conclusion: This simplified TLH procedure may be a safe and effective alternative for laparoscopic beginners as it is similar to that of abdominal hysterectomy. Furthermore, the exclusion of complicated tissue peeling reduces operator stress and surgery-related complications.