High-performance Ge/Si electro-absorption optical modulator up to 85°C and its highly efficient photodetector operation.

We studied a high-speed Ge/Si electro-absorption optical modulator (EAM) evanescently coupled with a Si waveguide of a lateral p-n junction for a high-bandwidth optical interconnect over a wide range of temperatures from 25 °C to 85 °C. We demonstrated 56 Gbps high-speed operation at temperatures up to 85 °C. From the photoluminescence spectra, we confirmed that the bandgap energy dependence on temperature is relatively small, which is consistent with the shift in the operation wavelengths with increasing temperature for a Ge/Si EAM. We also demonstrated that the same device operates as a high-speed and high-efficiency Ge photodetector with the Franz-Keldysh (F-K) and avalanche-multiplication effects. These results demonstrate that the Ge/Si stacked structure is promising for both high-performance optical modulators and photodetectors integrated on Si platforms.

High-speed Ge/Si electro-absorption optical modulator in C-band operation wavelengths.

We studied a high-speed electro-absorption optical modulator (EAM) of a Ge layer evanescently coupled with a Si waveguide (Si WG) of a lateral pn junction for high-bandwidth optical interconnect. By decreasing the widths of selectively grown Ge layers below 1 µm, we demonstrated a high-speed modulation of 56 Gbps non-return-to-zero (NRZ) and 56 Gbaud pulse amplitude modulation 4 (PAM4) EAM operation in the C-band wavelengths, in contrast to the L-band wavelengths operations in previous studies on EAMs of pure Ge on Si. From the photoluminescence and Raman analyses, we confirmed an increase in the direct bandgap energy for such a submicron Ge/Si stack structure. The operation wavelength for the Ge/Si stack structure of a Ge/Si EAM was optimized by decreasing the device width below 1-µm and setting the post-growth anneal condition, which would contribute to relaxing the tensile-strain of a Ge layer on a Si WG and broadening the optical bandwidths for Franz-Keldysh (FK) effect with SiGe alloy formation.

Preparation of Continuous Highly Hydrophobic Pure Silica ITQ-29 Zeolite Layers on Alumina Supports.

The preparation of continuous layers of highly hydrophobic pure silica ITQ-29 zeolite, potentially applicable as hydrophobic membranes for separation of molecules based on their polarity, has been investigated. Continuous layers of intergrown ITQ-29 zeolite crystals were successfully grown on porous alumina supports by optimization of the synthesis conditions, such as the appropriate selection of the seeds, the procedure for the gel preparation, and the calcination conditions. This resulted in the formation of all silica ITQ-29 zeolite layers without the presence of germanium required in previously reported ITQ-29 membranes, with the subsequent improvement in quality and stability, as verified by the absence of cracks after calcination. We have proved that the incorporation of aluminum from the support into the zeolite layer does not occur, neither during the secondary growth nor through migration of aluminum species during calcination.

The anti-influenza drug oseltamivir evokes hypothermia in mice through dopamine D2 receptor activation via central actions.

Oseltamivir has a hypothermic effect in mice when injected intraperitoneally (i.p.) and intracerebroventricularly (i.c.v.). Here we show that the hypothermia evoked by i.c.v.-oseltamivir is inhibited by non-selective dopamine receptor antagonists (sulpiride and haloperidol) and the D2-selective antagonist L-741,626, but not by D1/D5-selective and D3-selective antagonists (SCH-23390 and SB-277011-A, respectively). The hypothermic effect of i.p.-administered oseltamivir was not inhibited by sulpiride, haloperidol, L-741,626 and SCH-23390. In addition, neither sulpiride, haloperidol nor SCH-23390 blocked hypothermia evoked by i.c.v.-administered oseltamivir carboxylate (a hydrolyzed metabolite of oseltamivir). These results suggest that oseltamivir in the brain induces hypothermia through activation of dopamine D2 receptors.

Serotonergic System Does Not Contribute to the Hypothermic Action of Acetaminophen.

Acetaminophen (AcAP), a widely-used antipyretic and analgesic drug, has been considered to exert its effects via central mechanisms, and many studies have demonstrated that the analgesic action of AcAP involves activation of the serotonergic system. Although the serotonergic system also plays an important role in thermoregulation, the contribution of serotonergic activity to the hypothermic effect of AcAP has remained unclear. In the present study, we examined whether the serotonergic system is involved in AcAP-induced hypothermia. In normal mice, AcAP (300 mg/kg, intraperitoneally (i.p.)) induced marked hypothermia (ca. -4°C). The same dose of AcAP reduced pain response behavior in the formalin test. Pretreatment with the serotonin synthesis inhibitor DL-p-chlorophenylalanine (PCPA, 300 mg/kg/d, i.p., 5 consecutive days) substantially decreased serotonin in the brain by 70% and significantly inhibited the analgesic, but not the hypothermic action of AcAP. The same PCPA treatment significantly inhibited the hypothermia induced by the selective serotonin reuptake inhibitor fluoxetine hydrochloride (20 mg/kg, i.p.) and the serotonin 5-HT2 receptor antagonist cyproheptadine hydrochloride (3 mg/kg, i.p.). The lower doses of fluoxetine hydrochloride (3 mg/kg, i.p.) and cyproheptadine hydrochloride (0.3 mg/kg, i.p.) did not affect the AcAP-induced hypothermia. These results suggest that, in comparison with its analgesic effect, the hypothermic effect of AcAP is not mediated by the serotonergic system.

Oxaliplatin treatment changes the function of sensory nerves in rats.

Oxaliplatin (L-OHP) is a platinum-based chemotherapy drug, used in standard treatment of colorectal cancer. L-OHP frequently causes acute peripheral neuropathies. These adverse effects limit cancer therapy with L-OHP. The present study was designed to reveal the changes in sensory nerve function in L-OHP-injected rats. Mechanical static allodynia, dynamic allodynia, and cold allodynia were evaluated using the von Frey test, brush test, and acetone test, respectively. Sensory nerve fiber responsiveness was measured using a Neurometer. The fifth lumbar ventral root was sectioned to record multi-unit efferent discharges. Single intraperitoneal administration of L-OHP induced mechanical static allodynia, dynamic allodynia, and cold allodynia in Wistar/ST rats. The thresholds for paw withdrawal induced by 2000 Hz (Aß-fiber) and 5 Hz (C-fiber), but not 250 Hz (Aδ-fiber) sine-wave electrical stimulation were reduced in L-OHP-treated rats. Multi-unit efferent discharges were increased by mechanical stimulation using a von Frey filament applied to the plantar surface of the hindpaw. The discharges during and after stimulation were increased in the L-OHP-treated rats. Cold stimulation, but not brush stimulation, increased the discharges in L-OHP-treated rats. These results suggest that sensitization of Aß- and C-fibers, but not Aδ-fibers, contributes to the development of L-OHP-induced mechanical and cold allodynia.

Presynaptic inhibitory effects of fluvoxamine, a selective serotonin reuptake inhibitor, on nociceptive excitatory synaptic transmission in spinal superficial dorsal horn neurons of adult mice.

Fluvoxamine, a selective serotonin (5-HT) reuptake inhibitor, has been shown to exert analgesic effects in humans and laboratory animals. However, its effects on spinal nociceptive synaptic transmission have not been fully characterized. Here, whole-cell recordings were made from dorsal horn neurons in spinal slices with attached dorsal roots from adult mice, and the effects of fluvoxamine on monosynaptic A-fiber- and C-fiber-mediated excitatory postsynaptic currents (EPSCs) evoked in response to electrical stimulation of a dorsal root were studied. Fluvoxamine (10 - 100 µM) concentration-dependently suppressed both monosynaptic A-fiber- and C-fiber-mediated EPSCs, which were attenuated by the selective 5-HT1A receptor antagonist WAY100635. In the presence of the selective 5-HT3 receptor antagonist tropisetron, fluvoxamine hardly suppressed A-fiber-mediated EPSCs, whereas its inhibitory effect on C-fiber-mediated EPSCs was not affected. Although fluvoxamine increased the paired-pulse ratio of A-fiber-mediated EPSCs, it increased the frequency of spontaneous and miniature EPSCs (sEPSCs and mEPSCs). Since sEPSCs and mEPSCs appeared to arise largely from spinal interneurons, we then recorded strontium-evoked asynchronous events occurring after A-fiber stimulation, whose frequency was reduced by fluvoxamine. These results suggest that fluvoxamine reduces excitatory synaptic transmission from primary afferent fibers via presynaptic mechanisms involving 5-HT1A and/or 5-HT3 receptors, which may contribute to its analgesic effects.

Gabapentin prevents oxaliplatin-induced mechanical hyperalgesia in mice.

Oxaliplatin, a platinum-based chemotherapy drug, frequently causes acute and chronic peripheral neuropathies including mechanical hyperalgesia. These adverse effects hinder anticancer therapy with the drug. In this study, we examined several drugs that might prevent oxaliplatin-induced peripheral neuropathy. Single intraperitoneal (i.p.) injection of oxaliplatin (10 mg/kg) induced cold allodynia (acetone test) and mechanical hyperalgesia (von Frey test). Gabapentin, but not simvastatin and atorvastatin, prevented oxaliplatin-induced mechanical hyperalgesia without affecting cold allodynia. Moreover, oxaliplatin caused phosphorylation of cofilin protein in the spinal cord, which has been shown to be involved in the neuropathic hyperalgesia. This increased phosphorylation of cofilin was also attenuated by gabapentin treatment. These results suggest that gabapentin is useful for relieving oxaliplatin-induced mechanical hyperalgesia and that the pathogenic mechanisms of cold allodynia and mechanical hyperalgesia differ.

Contribution of TRPV1 receptor-expressing fibers to spinal ventral root after-discharges and mechanical hyperalgesia in a spared nerve injury (SNI) rat model.

Neuropathic pain induces allodynia and hyperalgesia. In the spared nerve injury (SNI) model, marked mechanical hyperalgesia is manifested as prolongation of the duration of paw withdrawal after pin stimulation. We have previously reported that spinal ventral root discharges (after-discharges) after cessation of noxious mechanical stimulation applied to the corresponding hindpaw were prolonged in anesthetized spinalized rats. Since these after-discharges occurred through transient receptor potential (TRP) V1-positive fibers, these fibers could contribute to mechanical hyperalgesia. Therefore, we examined whether selective deletion of TRPV1-positive fibers by resiniferatoxin, an ultrapotent TRPV1 agonist, would affect the behavioral changes and ventral root discharges in SNI rats. Mechanical allodynia in the von Frey test, mechanical hyperalgesia after pin stimulation, and enhancement of ventral root discharges, but not thermal hyperalgesia in the plantar test, appeared in Wistar rats with SNI. Mechanical hyperalgesia was abolished by treatment with resiniferatoxin, whereas mechanical allodynia was not affected. Moreover, resiniferatoxin eliminated after-discharges completely. These results show that TRPV1-positive fibers do not participate in the mechanical allodynia caused by sensitization of Aß-fibers, but contribute to the enhancement of after-discharges and mechanical hyperalgesia following SNI. It is suggested that the mechanisms responsible for generating mechanical allodynia differ from those for prolongation of mechanical hyperalgesia.

Incidentally Detected Extramedullary Plasmacytoma of the Gallbladder: A Case Report and Literature Review.

Extramedullary plasmacytoma (EMP) can rarely occur in conjunction with multiple myeloma (MM). EMPs are usually detected in the upper aerodigestive tract (UAD) but can also occur along the digestive tract. However, the involvement of gallbladder is uncommon. Gastrointestinal tract symptoms often lead to the diagnosis of EMP in the gallbladder. An 81-year-old man was referred to our hospital with suspected primary gallbladder carcinoma. He was subsequently operated on, and the pathological findings showed EMP of the gallbladder without MM.

N- and L-type voltage-dependent Ca2+ channels contribute to the generation of after-discharges in the spinal ventral root after cessation of noxious mechanical stimulation.

Voltage-dependent Ca(2+) channels (VDCCs) play a crucial role in the spinal pain transduction. We previously reported that nociceptive mechanical stimuli to the rat hindpaw evoked two types of ventral root discharges that increased during stimulation (during-discharges) and after cessation of stimulation (after-discharges). To explore the involvement of VDCCs in these ventral root discharges, several VDCC blockers were applied directly to the surface of the spinal cord. Spinalized rats were laminectomized. The fifth lumbar ventral root was sectioned and used for multi-unit efferent discharges recording. An agar pool was constructed on the first lumbar vertebra for drug application. Ethosuximide (a T-type VDCC blocker) had no effect on ventral root discharges. ω-Conotoxin GVIA (an N-type VDCC blocker) preferentially suppressed after-discharges. ω-Agatoxin IVA (a P/Q-type VDCC blocker), diltiazem, and verapamil (L-type VDCC blockers) nonselectively depressed both during- and after-discharges. The more selective L-type VDCC blocker nicardipine depressed only after-discharges and the depression was exhibited when nicardipine was microinjected into the dorsal horn, but not into the ventral horn. These findings suggested that N- and L-type VDCCs in the dorsal horn were involved in the generation of after-discharges and these blockers might be useful for treatment of persistent pain that involves the spinal pathway.

Effect of spinally administered simvastatin on the formalin-induced nociceptive response in mice.

Clinical and experimental observations indicated that 3-hydroxy-3-methylglutaryl CoA reductase inhibitor statins have pleiotropic effects. The present study determined the antinociceptive property of centrally administered simvastatin on the formalin-induced nociception in the mouse. Intrathecal administration of simvastatin at doses of 0.5 - 50 nmol dose-dependently attenuated the second, but not the first, phase of the formalin-induced nociception, which was partially reversed by mevalonate (5 µmol). Intracerebroventricular injection of simvastatin (50 nmol) did not affect the formalin-induced nociception. These results suggest that simvastatin-induced antinociception is mediated by attenuation of the sensitization of spinal nociceptive transmission.

Endoscopic Removal of Multiple Ingested Cylindrical Batteries.

Button battery ingestion accidents have been reported in multiple previous reports. However, ingestion of cylindrical-type batteries is significant less described in the literature. Cylindrical batteries can reportedly cause corrosive damage to the gastrointestinal mucosa after long-term retention, leading to ulceration and perforation. Here, we present a case of endoscopic removal of eight AA batteries that had been ingested and caused corrosive changes in the gastrointestinal mucosa. A 45-year-old man with mental retardation was brought to our hospital due to the suspicion of cylindrical battery ingestion. A plain abdominal x-ray revealed a total of eight cylindrical batteries. Esophagogastroduodenoscopy was performed approximately 24 hours after ingestion, and four AA batteries were removed using a polypectomy snare. The remaining four batteries were followed up and removed under colonoscopy after confirming that they had reached the rectum. Leaked components of retained cylindrical batteries can cause chemical mucosal damage in the gastrointestinal tract. Therefore, early extraction should be considered in case of cylindrical battery ingestion. On the other hand, when the cylindrical battery has passed the pyloric ring, conservative management with close monitoring is acceptable if there are no clinical symptoms. Additionally, a polypectomy snare is useful in the extraction of ingested cylindrical batteries.

Diagnostic Strategy of Early Stage Pancreatic Cancer via Clinical Predictor Assessment: Clinical Indicators, Risk Factors and Imaging Findings.

Early detection of pancreatic ductal adenocarcinoma (PDAC) in the general population is difficult due to unknown clinical characteristics. This study was conducted to clarify the factors associated with early stage PDAC. Well-known symptoms and factors associated with PDAC were classified into clinical indicators, risk factors, and imaging findings concomitant with early stage PDAC. To analyze these factors for the detection of patients with early stage PDAC compared to patients without PDAC, we constructed new diagnostic strategies. The factors of 35 patients with early stage PDAC (stage 0 and IA) and 801 patients without PDAC were compared retrospectively. Clinical indicators; presence and number of indicators, elevated pancreatic enzyme level, tumor biomarker level, acute pancreatitis history, risk factors; familial pancreatic cancer, diabetes mellitus, smoking history, imaging findings; presence and number of findings, and main pancreatic duct dilation were significant factors for early stage PDAC detection. A new screening strategy to select patients who should be examined by imaging modalities from evaluating clinical indicators and risk factors and approaching a definitive diagnosis by evaluating imaging findings had a relatively high sensitivity, specificity, and areas under the curve of 80.0%, 80.8%, and 0.80, respectively. Diagnosis based on the new category and strategy may be reasonable for early stage PDAC detection.

Towards universal neural network potential for material discovery applicable to arbitrary combination of 45 elements.

Computational material discovery is under intense study owing to its ability to explore the vast space of chemical systems. Neural network potentials (NNPs) have been shown to be particularly effective in conducting atomistic simulations for such purposes. However, existing NNPs are generally designed for narrow target materials, making them unsuitable for broader applications in material discovery. Here we report a development of universal NNP called PreFerred Potential (PFP), which is able to handle any combination of 45 elements. Particular emphasis is placed on the datasets, which include a diverse set of virtual structures used to attain the universality. We demonstrated the applicability of PFP in selected domains: lithium diffusion in LiFeSO4F, molecular adsorption in metal-organic frameworks, an order-disorder transition of Cu-Au alloys, and material discovery for a Fischer-Tropsch catalyst. They showcase the power of PFP, and this technology provides a highly useful tool for material discovery.

Monomorphic epitheliotropic intestinal T-cell lymphoma presenting as melena with long-term survival: A case report and review of literature.

BACKGROUND: Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare primary intestinal T-cell lymphoma, previously known as enteropathy-associated T-cell lymphoma type II. MEITL is an aggressive T-cell lymphoma with a poor prognosis and high mortality rate. The known major complications of MEITL are intestinal perforation and obstruction. Here, we present a case of MEITL that was diagnosed following upper gastrointestinal bleeding from an ulcerative duodenal lesion, with recurrence-free survival for 5 years. CASE SUMMARY: A 68-year-old female was admitted to our hospital with melena and mild anemia. An urgent esophagogastroduodenoscopy (EGD) revealed bleeding from an ulcerative lesion in the transverse part of the duodenum, for which hemostatic treatment was performed. MEITL was diagnosed following repeated biopsies of the lesion, and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy was administered. She achieved complete remission after eight full cycles of CHOP therapy. At the last follow-up examination, EGD revealed a scarred ulcer and 18Fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography showed no abnormal FDG accumulation. The patient has been in complete remission for 68 mo after initial diagnosis. CONCLUSION: To rule out MEITL, it is important to carefully perform histological examination when bleeding from a duodenal ulcer is observed.

Neuroprotection via strychnine-sensitive glycine receptors during post-ischemic recovery of excitatory synaptic transmission in the hippocampus.

Recent evidence indicates that strychnine-sensitive glycine receptors are located in upper brain regions including the hippocampus. Because of excitatory effects of glycine via facilitation of NMDA-receptor function, however, the net effects of increased extracellular glycine on neuronal excitability in either physiological or pathophysiological conditions are mostly unclear. Here, we addressed the potential neuroprotective effect of either exogenous application of glycine and taurine, which are both strychnine-sensitive glycine-receptor agonists, or an endogenous increase of glycine via blockade of glycine transporter 1 (GlyT1) by assessing their ability to facilitate the functional recovery of field excitatory postsynaptic potentials (fEPSPs) after termination of brief oxygen/glucose deprivation (OGD) in the CA1 region in mouse hippocampal slices. Glycine and taurine promoted restoration of the fEPSPs after reperfusion, but this was never observed in the presence of strychnine. Interestingly, glycine and taurine appeared to generate neuroprotective effects only at their optimum concentration range. By contrast, blockade of GlyT1 by N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)propyl]sarcosine or sarcosine did not elicit significant neuroprotection. These results suggest that activation of strychnine-sensitive glycine receptors potentially produces neuroprotection against metabolic stress such as OGD. However, GlyT1 inhibition is unlikely to elicit a sufficient increase in the extracellular level of glycine to generate neuroprotection.

Intracerebroventricular Treatment with Resiniferatoxin and Pain Tests in Mice.

The transient receptor potential vanilloid type 1 (TRPV1), a thermosensitive cation channel, is known to trigger pain in the peripheral nerves. In addition to its peripheral function, its involvement in brain functions has also been suggested. Resiniferatoxin (RTX), an ultrapotent TRPV1 agonist, has been known to induce long-term desensitization of TRPV1, and this desensitization has been an alternative approach for investigating the physiological relevance of TRPV1-expressing cells. Here we describe a protocol for intracerebroventricular (i.c.v.) treatment with RTX in mice. Procedures are described for testing nociception to peripheral TRPV1 stimulation (RTX test) and mechanical stimulation (tail pressure test) then follow. Although the nociceptive responses of mice that had been administered RTX i.c.v. were comparable to those of the control groups, RTX-i.c.v.-administered mice were insensitive to the analgesic effect of acetaminophen, suggesting that i.c.v. RTX treatment can induce supraspinal-selective TRPV1 desensitization. This mouse model can be used as a convenient experimental system for studying the role of TRPV1 in brain/supraspinal function. These techniques can also be applied to studies of the central actions of other drugs.

A case of ruptured mucinous cystadenoma of the pancreas with recurrence-free survival for 8 years.

BACKGROUND: Pancreatic mucinous cystic neoplasm (MCM) presenting with rupture is extremely rare, and very few studies have followed up patients over the long term after ruptured mucinous cystadenoma (MCA). We report a case of ruptured MCA of the pancreas with recurrence-free survival for 8 years. CASE PRESENTATION: A 28-year-old Japanese woman was admitted to the emergency department of a local hospital after experiencing acute abdominal pain. Abdominal computed tomography revealed massive ascites and the presence of a cystic tumor measuring 60 mm in diameter in the pancreatic tail. Conservative therapy with antibiotics and abdominal drainage were performed to treat peritonitis that occurred secondary to the ruptured pancreatic cystic tumor, after which the patient's symptoms improved. The patient was referred to our department for further examination and treatment. We diagnosed a ruptured MCN and performed laparoscopic spleen-preserving distal pancreatectomy. Histopathological findings revealed ovarian-type stroma, which tested positive for estrogen and progesterone receptors by immunohistochemistry. The histopathological diagnosis was MCA. The postoperative course was uneventful, and the patient remains alive without any evidence of recurrence at 8 years postoperatively. CONCLUSION: A good prognosis is possible even in cases of ruptured MCA. Because of the risk of peritoneal dissemination after ruptured MCA, long-term follow-up is important.