Automation of etch pit analyses on solid-state nuclear track detectors with machine learning for laser-driven ion acceleration.

Solid-state nuclear track detectors (SSNTDs) are often used as ion detectors in laser-driven ion acceleration experiments and are considered to be the most reliable ion diagnostics since they are sensitive only to ions and measure ions one by one. However, ion pit analyses require tremendous time and effort in chemical etching, microscope scanning, and ion pit identification by eyes. From a laser-driven ion acceleration experiment, there are typically millions of microscopic images, and it is practically impossible to analyze all of them by hand. This research aims to improve the efficiency and automation of SSNTD analyses for laser-driven ion acceleration. We use two sets of data obtained from calibration experiments with a conventional accelerator where ions with known nuclides and energies are generated and from actual laser experiments using SSNTDs. After chemical etching and scanning the SSNTDs with an optical microscope, we use machine learning to distinguish the ion etch pits from noises. From the results of the calibration experiment, we confirm highly accurate etch-pit detection with machine learning. We are also able to detect etch pits with machine learning from the laser-driven ion acceleration experiment, which is much noisier than calibration experiments. By using machine learning, we successfully identify ion etch pits ∼105 from more than 10 000 microscopic images with a precision of ≳95%. A million microscopic images can be examined with a recent entry-level computer within a day with high precision. Machine learning tremendously reduces the time consumption on ion etch pit analyses detected on SSNTDs.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest.

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Robustness of large-area suspended graphene under interaction with intense laser.

Graphene is known as an atomically thin, transparent, highly electrically and thermally conductive, light-weight, and the strongest 2D material. We investigate disruptive application of graphene as a target of laser-driven ion acceleration. We develop large-area suspended graphene (LSG) and by transferring graphene layer by layer we control the thickness with precision down to a single atomic layer. Direct irradiations of the LSG targets generate MeV protons and carbons from sub-relativistic to relativistic laser intensities from low contrast to high contrast conditions without plasma mirror, evidently showing the durability of graphene.

Interaction of Bnr1p with a novel Src homology 3 domain-containing Hof1p. Implication in cytokinesis in Saccharomyces cerevisiae.

Proteins containing the formin homology (FH) domains FH1 and FH2 are involved in cytokinesis or establishment of cell polarity in a variety of organisms. We have shown that the FH proteins Bni1p and Bnr1p are potential targets of the Rho family small GTP-binding proteins and bind to an actin-binding protein, profilin, at their proline-rich FH1 domains to regulate reorganization of the actin cytoskeleton in the yeast Saccharomyces cerevisiae. We found here that a novel Src homology 3 (SH3) domain-containing protein, encoded by YMR032w, interacted with Bnr1p in a GTP-Rho4p-dependent manner through the FH1 domain of Bnr1p and the SH3 domain of Ymr032wp. Ymr032wp weakly bound to Bni1p. Ymr032wp was homologous to cdc15p, which is involved in cytokinesis in Schizosaccharomyces pombe, and we named this gene HOF1 (homolog of cdc 15). Both Bnr1p and Hof1p were localized at the bud neck, and both the bnr1 and hof1 mutations showed synthetic lethal interactions with the bni1 mutation. The hof1 mutant cells showed phenotypes similar to those of the septin mutants, indicating that HOF1 is involved in cytokinesis. These results indicate that Bnr1p directly interacts with Hof1p as well as with profilin to regulate cytoskeletal functions in S. cerevisiae.

Bni1p and Bnr1p: downstream targets of the Rho family small G-proteins which interact with profilin and regulate actin cytoskeleton in Saccharomyces cerevisiae.

The RHO1 gene encodes a homologue of mammalian RhoA small G-protein in the yeast Saccharomyces cerevisiae. Rho1p is required for bud formation and is localized at a bud tip or a cytokinesis site. We have recently shown that Bni1p is a potential target of Rho1p. Bni1p shares the FH1 and FH2 domains with proteins involved in cytokinesis or establishment of cell polarity. In S. cerevisiae, there is an open reading frame (YIL159W) which encodes another protein having the FH1 and FH2 domains and we have named this gene BNR1 (BNI1 Related). Bnr1p interacts with another Rho family member, Rho4p, but not with Rho1p. Disruption of BNI1 or BNR1 does not show any deleterious effect on cell growth, but the bni1 bnr1 mutant shows a severe temperature-sensitive growth phenotype. Cells of the bni1 bnr1 mutant arrested at the restrictive temperature are deficient in bud emergence, exhibit a random distribution of cortical actin patches and often become multinucleate. These phenotypes are similar to those of the mutant of PFY1, which encodes profilin, an actin-binding protein. Moreover, yeast two-hybrid and biochemical studies demonstrate that Bni1p and Bnr1p interact directly with profilin at the FH1 domains. These results indicate that Bni1p and Bnr1p are potential targets of the Rho family members, interact with profilin and regulate the reorganization of actin cytoskeleton.

ROM7/BEM4 encodes a novel protein that interacts with the Rho1p small GTP-binding protein in Saccharomyces cerevisiae.

The RHO1 gene encodes a homolog of the mammalian RhoA small GTP-binding protein in the yeast Saccharomyces cerevisiae. Rho1p is localized at the growth site and is required for bud formation. The RHO1(G22S, D125N) mutation is a temperature-sensitive and dominant negative mutation of RHO1, and a multicopy suppressor of RHO1(G22S, D125N), ROM7, was isolated. Nucleotide sequencing of ROM7 revealed that it is identical to the BEM4 gene (GenBank accession number L27816), although its physiological function has not yet been reported. Disruption of BEM4 resulted in the cold- and temperature-sensitive growth phenotypes, and cells of the deltabem4 mutant showed abnormal morphology, suggesting that BEM4 is involved in the budding process. The temperature-sensitive growth phenotype was suppressed by overexpression of RHO1, ROM2, which encodes a Rho1p-specific GDP/GTP exchange factor, or PKC1, which encodes a target of Rho1p. Moreover, glucan synthase activity, which is activated by Rho1p, was significantly reduced in the deltabem4 mutant. Two-hybrid and biochemical experiments revealed that Bem4p directly interacts with the nucleotide-free form of Rho1p and, to lesser extents, with the GDP- and GTP-bound forms of Rho1p, although Bem4p showed neither GDP/GTP exchange factor, GDP dissociation inhibitor, nor GTPase-activating protein activity toward Rho1p. These results indicate that Bem4p is a novel protein directly interacting with Rho1p and is involved in the RHO1-mediated signaling pathway.

Rom1p and Rom2p are GDP/GTP exchange proteins (GEPs) for the Rho1p small GTP binding protein in Saccharomyces cerevisiae.

The RHO1 gene encodes a homolog of the mammalian RhoA small GTP binding protein in the yeast Saccharomyces cerevisiae. Rho1p is localized at the growth site and is required for bud formation. Multicopy suppressors of a temperature-sensitive, dominant negative mutant allele of RHO1, RHO1(G22S, D125N), were isolated and named ROM (RHO1 multicopy suppressor). Rom1p and Rom2p were found to contain a DH (Dbl homologous) domain and a PH (pleckstrin homologous) domain, both of which are conserved among the GDP/GTP exchange proteins (GEPs) for the Rho family small GTP binding proteins. Disruption of ROM2 resulted in a temperature-sensitive growth phenotype, whereas disruption of both ROM1 and ROM2 resulted in lethality. The phenotypes of deltarom1deltarom2 cells were similar to those of deltarho1 cells, including growth arrest with a small bud and cell lysis. Moreover, the temperature-sensitive growth phenotype of deltarom2 was suppressed by overexpression of RHO1 or RHO2, but not of CDC42. The glutathione-S-transferase (GST) fusion protein containing the DH domain of Rom2p showed the lipid-modified Rholp-specific GDP/GTP exchange activity which was sensitive to Rho GDP dissociation inhibitor. These results indicate that Rom1p and Rom2p are GEPs that activate Rho1p in S.cerevisiae.

[Statistic studies on bacteria isolated from urinary tract infections (report 6: isolation rate and drug sensitivity from 1988 through 1989)].

We examined the bacteria isolated from urine of patients in our department from 1988 though 1989. A total of 809 strains were isolated from the outpatients. They were 241 strains of gram-positive bacteria (29.8%). E. coli (32.0%) was isolated most frequently, followed by Enterococcus spp. (9.9%), Proteus group (7.4%), S. epidermidis (6.2%), P. aeruginosa (5.1%) and others. A total of 412 strains were isolated from the inpatients. They consisted of 173 strains of gram-positive bacteria (42.0%). Enterococcus spp. (17.0%) was isolated most frequently, followed by P. aeruginosa (12.6%), S. epidermidis (9.7%), E. coli (7.3%), S. aureus (6.6%) and others. Fewer P. aeruginosa, S. marcescens and Proteus group were isolated from the outpatients and fewer S. marcescens, E. coli and K. pneumoniae from inpatients than previously. More S. aureus were isolated abruptly from the inpatients and more E. coli were isolated from the outpatients than previously. E. cloacae, S. epidermidis, S. aureus and Corynebacterium spp. all isolated from inpatients showed lower antimicrobial sensitivity than those isolated from the outpatients.

[Urinary extravasation: report of five cases and review of the Japanese literature].

We studied the etiology, diagnosis and management of 201 cases of urinary extravasation reported in the Japanese literature along with our five cases. Most of them were caused by urolithiasis and malignant tumors. Four of our five cases also presented with a ureter stone; two being cured by spontaneous stone passage within several days and the others being treated by ureterolithotomy or nephrectomy. The other case involving a ureter tumor was treated by nephroureterectomy with partial cystectomy. The clinical manifestations of urinary extravasation were distinguished as spontaneous peripelvic extravasation and spontaneous rupture of the renal pelvis and ureter. Performing an accurate and differential diagnosis of these cases, however, was difficult. We therefore propose a set of clinical diagnostic criteria based on our findings of X-ray examination and the macroscopic appearance seen during surgical treatment. We review the 201 reported cases along with our five cases of urinary extravasation and discuss their diagnostic procedures and treatment approaches.

MR imaging of seminal vesicle cysts associated with adult polycystic kidney disease.

An unusual case of seminal vesicle cysts associated with adult polycystic kidney disease (APKD) is presented. The magnetic resonance (MR) appearance of this rare entity has not been described before. A brief review of the literature is included and the role of MR imaging is discussed.

[Contralateral ureteral metastasis from renal cell carcinoma: a case report].

A case of contralateral ureteral metastasis from renal cell carcinoma is reported. A 52-year-old man underwent left nephrectomy for renal cell carcinoma of November 20, 1986. He was clinically asymptomatic for 4 years 8 months after the operation. He was admitted on August 14, 1991, because of right loin pain. Right retrograde pyelography and percutaneous pyelography showed a filling defect in the right ureter at the level of L3. After the right ureter was explored, the tumor lesion of ureter was resected and end to end anastomosis of the ureter was performed. Histopathologic examination showed a metastatic clear cell carcinoma consistent with a renal primary. The contralateral ureteral metastasis from renal cell carcinoma is very rare and only 15 cases have been reported previously.

Multilocular cystic hemangioma: CT and MR appearance.

An atypical case of multilocular cystic hemangioma is presented. A 4.5 cm multilocular cystic mass was incidentally found in a 66-year-old healthy woman on ultrasound screening. CT, MR imaging, and angiography were performed: however, the features that are characteristic of cavernous hemangioma were not obtained. The final diagnosis could not be made until surgery.

[A case of metastatic urinary bladder tumor from gastric carcinoma].

We report a case of metastatic bladder tumor from gastric carcinoma. A 55-year old male patient was referred to our urological clinic with a complaint of frequent urination and voiding pain. He had undergone total gastrectomy for poorly differentiated adenocarcinoma, signet-ring cell type, 9 months earlier. Computed tomographic scan revealed a thick bladder and rectum wall all around. Punch biopsies from vesical and rectal wall revealed metastatic adenocarcinoma, signet-ring cell type. There were no other metastatic sites. Systemic chemotherapy was done with a combination of mitomycin-C, 5-fluorouracil and cytosine arabinoside. This chemotherapy was effective and complete remission was obtained at bladder and rectum. Six months after chemotherapy, peritoneal recurrence developed and he died 9 months after chemotherapy. However no recurrence of bladder tumor was detected. This was a quite rare case of metastatic bladder tumor characterized by good response to systemic chemotherapy.

[Primary osteosarcoma of the bladder: a case report].

A case report of primary osteosarcoma of the bladder is herein presented. A 75-year-old man presented with asymptomatic macrohematuria. Cystoscopic examination revealed a large tumor with a broad base arisen on the anterior wall. Pelvic computed tomographic scan showed multiple calcifications in the tumor itself. Total cystectomy and ileal conduit were performed. Histopathological diagnosis was osteosarcoma. The patient died 10 weeks after surgery. Metastasis to lung, heart, lymphnode, ureter and peritoneum were identified by autopsy. Primary osteosarcoma of the bladder is a rare tumor, only 25 cases have been reported previously. The prognosis of this tumor is very poor. Nineteen of these patients died within 6 months.

Dense parenchymal accumulation of Lipiodol after transarterial chemoembolization.

Dense accumulation of Lipiodol in hepatic segmental parenchyma was studied by computed tomography (CT) after transarterial chemoembolization (TACE) for hepatic tumor. Six patients showed dense accumulation of Lipiodol in hepatic segmental parenchyma on CT two weeks after TACE. Four of the six showed parenchymal accumulation of Lipiodol as dense as that in a tumor at three weeks after TACE. Therefore, it was considered that evaluation with CT should be performed after one month or more in order to differentiate between Lipiodol accumulation in tumors and that in non-neoplastic liver parenchyma.

MR imaging of malignant mesenchymal tumors of the liver.

Magnetic resonance (MR) features of five primary malignant mesenchymal neoplasms (plasmocytoma, leiomyosarcoma, undifferentiated sarcoma, epithelioid hemangioendothelioma, and angiosarcoma) of the liver were reported. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. No halo and intravenous extension were noted. A target appearance was revealed in epithelioid hemangioendothelioma. MR findings of angiosarcoma were essentially the same as those of cavernous hemangiomas (markedly hyperintense with hypointense linear septa on T2-weighted images). MR findings of these rare hepatic malignancies were nonspecific, although they were quite different from those of typical hepatocellular carcinomas. This study suggested that MR differentiation of primary hepatic mesenchymal tumors from other common benign and malignant neoplasms was difficult; however, the number of studied cases was limited.

[Clinical statistics on operations for inpatients at Department of Urology, Tokai University Hospital 1975-1989].

Operations on inpatients during the 15-year period from 1975 to 1989 were analyzed statistically. A total of 3,791 operations were performed at our Department of Urology, including 717 operations on the kidney, 316 operations on the ureter, 583 operations on the bladder, 811 operations on the prostate, 136 operations on the urethra, 1,097 operations on the scrotum, 43 operations on the adrenal gland, 19 operations on the retroperitoneal space and 69 operations on other organs.

[Giant müllerian duct cyst: a case report].

A case of giant müllerian duct cyst is reported. The patient was a 27-year-old male, complaining of microscopic hematuria. A giant cystic abdominal mass was palpable. After screening examination including ultrasound tomography, intravenous pyelography, computed tomography and magnetic resonance-imaging, müllerian duct cyst was suspected. Operation for this cyst was performed with median incision. The cyst measured 25 x 21 x 14 cm. The surface as smooth and consistency was soft. Included fluid was slightly turbid and yellowish measuring 2,200 ml. This was considered to be the largest müllerian duct cyst case reported in the Japanese literature.