L-Arginine treatment may prevent tubulointerstitial nephropathy caused by germanium dioxide

L-Arginine treatment may prevent tubulointerstitial nephropathy caused by germanium dioxide.BackgroundLong-term oral ingestion of germanium dioxide (GeO2) causes progressive renal failure derived from tubulointerstitial nephropathy in humans and animals. The characteristic of GeO2-induced nephropathy is the renal tissue injury persisting for a long time, even after cessation of GeO2 ingestion. However, a treatment that can suppress the long-lasting renal tissue injury has not yet been established.MethodsUsing the methods of immunohistochemistry and reverse transcription-polymerase chain reaction, we examined the expression of ED1-positive cells (macrophages/monocytes), transforming growth factor (TGF)-β1 mRNA and protein and collagen type IV mRNA and protein in the kidneys of rats with GeO2-induced nephropathy. Concomitantly, the effects of L-arginine treatment on their expression was explored in the kidneys of rats with GeO2-induced nephropathy.ResultsChronic administration of GeO2 caused tubulointerstitial nephropathy characterized by leukocyte invasion into the enlarged tubulointerstitial space in rats. The expression of ED1-positive cells, TGF-β1 protein and collagen type IV protein was markedly increased in the tubulointerstitium of the renal cortex from rats with GeO2-induced nephropathy. Similarly, TGF-β1 and collagen type IV mRNA were significantly enhanced in the renal cortex of rats with GeO2-induced nephropathy. A small number of tubulointerstitial cells expressing TGF-β1 protein were also observed in the renal cortex of rats with GeO2-induced nephropathy. However, L-arginine treatment led to a parallel decrease in the expression of ED1-positive cells, TGF-β1 mRNA and collagen type IV mRNA and protein in rats with GeO2-induced nephropathy.ConclusionsIn general, collagen synthesis is driven by TGF-β1 in the fibrotic process associated with a variety of renal disorders. TGF-β1 is secreted by TGF-β1 producing cells such as macrophages, fibroblasts and myofibroblasts. Thus, the present study indicates that the expression of collagen type IV may be mediated by TGF-β1 released from invading macrophages and, to a lesser extent, released from tubulointerstitial cells, presumably fibroblasts and/or myofibroblasts in GeO2-induced nephropathy. L-Arginine treatment inhibits collagen type IV synthesis possibly by suppressing macrophage invasion and the resultant TGF-β1 expression in this nephropathy. L-Arginine treatment may be beneficial in the prevention of tubulointerstitial fibrosis, which is considered to be the terminal stage of GeO2-induced nephropathy

Lagrange multiplier and singular limit of double obstacle problems for Allen-Cahn equation with constraint

We consider an Allen--Cahn equation with a constraint of double obstacle-type. This constraint is a subdifferential of an indicator function on the closed interval, which is a multivalued function. In this paper we study the properties of the Lagrange multiplier to our equation. Also, we consider the singular limit of our system and clarify the limit of the solution and the Lagrange multiplier to our double obstacle problem. Moreover, we give some numerical experiments of our problem by using the Lagrange multiplier

Demographic history and interspecific hybridization of four Shorea species (Dipterocarpaceae) from Peninsular Malaysia inferred from nucleotide polymorphism in nuclear gene regions

Shorea acuminata Dyer, Shorea curtisii Dyer ex King, Shorea leprosula Miq., and Shorea parvifolia Dyer are dominant tree species in the tropical rainforest of Peninsular Malaysia, which experienced several climatic changes during Pleistocene. To investigate the current population structure and demographic history of these species, we analyzed levels and patterns of nucleotide polymorphism of the nuclear gene region PgiC. We also used sequence data of the GapC gene region obtained in our previous study. Negative Tajima's D values observed in both investigated gene regions for S. curtisii, S. leprosula, and S. parvifolia implied that all three species have experienced population expansion events. Little to moderate levels of population differentiation in S. acuminata and S. curtisii suggested recent divergence of the investigated populations after postglacial colonization of the Peninsular Malaysia. In addition, some haplotypes were similar or identical to haplotypes of the other species. The existence of such haplotypes could be partially explained by interspecific hybridization. Indeed, we found some putative hybrid individuals. Interspecific hybridization among closely related species might have contributed to the polymorphism of the investigated species

Massive-mode polarization entangled biphoton frequency comb

Biphoton frequency comb (BFC) having quantum entanglement in a high dimensional system is widely applicable to quantum communication and quantum computation. However, a dozen mode realized so far has not been enough to realize its full potential. Here, we show a massive-mode BFC with polarization entanglement experimentally realized by a nonlinear optical waveguide resonator. The generated BFC at least 1400 modes is broad and dense, that strongly enhances the advantage of BFC. We also demonstrated a versatile property of the present BFC, which enables us to prepare both the frequency-multiplexed entangled photon pair and the high dimensional hyperentangled one. The versatile, stable and highly efficient system with the massive-mode BFC will open up a large-scale photonic quantum information platform.Comment: 16 pages, 8 figure

Feasibility of Endoscopy-Assisted Laparoscopic Full-Thickness Resection for Superficial Duodenal Neoplasms

Background. Superficial duodenal neoplasms (SDNs) are a challenging target in the digestive tract. Surgical resection is invasive, and it is difficult to determine the site and extent of the lesion from outside the intestine and resect it locally. Endoscopic submucosal dissection (ESD) has scarcely been utilized in the treatment of duodenal tumors because of technical difficulties and possible delayed perforation due to the action of digestive juices. Thus, no standard treatments for SDNs have been established. To challenge this issue, we elaborated endoscopy-assisted laparoscopic full-thickness resection (EALFTR) and analyzed its feasibility and safety. Methods. Twenty-four SDNs in 22 consecutive patients treated by EALFTR between January 2011 and July 2012 were analyzed retrospectively. Results. All lesions were removed en bloc. The lateral and vertical margins of the specimens were negative for tumor cells in all cases. The mean sizes of the resected specimens and lesions were 28.9 mm (SD ± 10.5) and 13.3 mm (SD ± 11.6), respectively. The mean operation time and intraoperative estimated blood loss were 133 min (SD ± 45.2) and 16 ml (SD ± 21.1), respectively. Anastomotic leakage occurred in three patients (13.6%) postoperatively, but all were minor leakage and recovered conservatively. Anastomotic stenosis or bleeding did not occur. Conclusions. EALFTR can be a safe and minimally invasive treatment option for SDNs. However, the number of cases in this study was small, and further accumulations of cases and investigation are necessary

Distribution of Japanese Eel Anguilla japonica Revealed by Environmental DNA

絶滅危惧種ニホンウナギの分布域を環境DNA解析で推定. 京都大学プレスリリース. 2021-03-03.The abundance of Japanese eel Anguilla japonica has rapidly decreased in recent decades. Following a re-evaluation of the possibility of extinction, the Japanese Ministry of the Environment and the International Union for Conservation of Nature listed the Japanese eel as an endangered species in 2013 and 2014, respectively. However, their abundance and precise distribution have never been clarified owing to their nocturnality and difficulty in their capture. In this study, the distribution of Japanese eels was investigated by monitoring for environmental DNA (eDNA), a non-invasive and efficient detection method. A total of 365 water samples were collected from 265 rivers located throughout Japan. High concentrations of eDNA of Japanese eels were detected in rivers on the Pacific side, but were low in the Sea of Japan side. In particular, very little eDNA amplification was confirmed from Hokkaido and the north of the Sea of Japan. The eDNA distribution in Japanese rivers coincides with the transport of the larvae in the ocean, as estimated by numerical simulations. Generalized linear mixed models were developed to explain the distribution of eDNA concentrations. The total nitrogen concentration emerged as an important factor in the best model. These results indicate that the distribution of Japanese eel is mostly determined by the maritime larval transport, and their survival and growth depend on the abundance of food in the river. The findings of the present study are useful for the management of populations and in the conservation of Japanese eels

A Comprehensive Study of Short Bursts from SGR 1806-20 and SGR 1900+14 Detected by HETE-2

We present the results of temporal and spectral studies of the short burst (less than a few hundred milliseconds) from the soft gamma repeaters (SGRs) 1806-20 and 1900+14 using the HETE-2 samples. In five years from 2001 to 2005, HETE-2 detected 50 bursts which were localized to SGR 1806-20 and 5 bursts which were localized to SGR 1900+14. Especially SGR 1806-20 was active in 2004, and HETE-2 localized 33 bursts in that year. The cumulative number-intensity distribution of SGR 1806-20 in 2004 is well described by a power law model with an index of -1.1+/-0.6. It is consistent with previous studies but burst data taken in other years clearly give a steeper distribution. This may suggest that more energetic bursts could occur more frequently in periods of greater activity. A power law cumulative number-intensity distribution is also known for earthquakes and solar flares. It may imply analogous triggering mechanisms. Although spectral evolution during bursts with a time scale of > 20 ms is not common in the HETE-2 sample, spectral softening due to the very rapid (< a few milliseconds) energy reinjection and cooling may not be excluded. The spectra of all short bursts are well reproduced by a two blackbody function (2BB) with temperatures ~4 and ~11 keV. From the timing analysis of the SGR 1806-20 data, a time lag of 2.2+/-0.4 ms is found between the 30-100 keV and 2-10 keV radiation bands. This may imply (1) a very rapid spectral softening and energy reinjection, (2) diffused (elongated) emission plasma along the magnetic field lines in pseudo equilibrium with multi-temperatures, or (3) a separate (located at < 700 km) emission region of softer component (say, ~4 keV) which could be reprocessed X-rays by higher energy (> 11 keV) photons from an emission region near the stellar surface.Comment: 50 pages, 14 figures, accepted for publication in PAS

Outburst of LS V+44 17 Observed by MAXI and RXTE, and Discovery of a Dip Structure in the Pulse Profile

We report on the first observation of an X-ray outburst of a Be/X-ray binary pulsar LS V +44 17/RX J0440.9+4431, and the discovery of an absorption dip structure in the pulse profile. An outburst of this source was discovered by MAXI GSC in 2010 April. It was the first detection of the transient activity of LS V +44 17 since the source was identified as a Be/X-ray binary in 1997. From the data of the follow-up RXTE observation near the peak of the outburst, we found a narrow dip structure in its pulse profile which was clearer in the lower energy bands. The pulse-phase-averaged energy spectra in the 3$-$100 keV band can be fitted with a continuum model containing a power-law function with an exponential cutoff and a blackbody component, which are modified at low energy by an absorption component. A weak iron K$\alpha$ emission line is also detected in the spectra. From the pulse-phase-resolved spectroscopy we found that the absorption column density at the dip phase was much higher than those in the other phases. The dip was not seen in the subsequent RXTE observations at lower flux levels. These results suggest that the dip in the pulse profile originates from the eclipse of the radiation from the neutron star by the accretion column.Comment: 18 pages, 7 figures, accepted for publication in PAS

The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images

The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the ISS. It is scheduled for launch in the middle of 2009 to monitor all-sky X-ray objects on every ISS orbit. MAXI will be more powerful than any previous X-ray All Sky Monitor (ASM) payloads, being able to monitor hundreds of AGN. MAXI will provide all sky images of X-ray sources of about 20 mCrab in the energy band of 2-30 keV from observation on one ISS orbit (90 min), about 4.5 mCrab for one day, and about 1 mCrab for one month. A final detectability of MAXI could be 0.2 mCrab for 2 year observations.Comment: 12 pages, 11 figures, accepted for publication in Publications of the Astronomical Society of Japa