Nonreciprocity of spin waves in the conical helix state.

Nonreciprocity emerges in nature and in artificial objects from various physical origins, being widely utilized in contemporary technologies as exemplified by diode elements in electronics. While most of the nonreciprocal phenomena are realized by employing interfaces where the inversion symmetry is trivially lifted, nonreciprocal transport of photons, electrons, magnons, and possibly phonons also emerge in bulk crystals with broken space inversion and time reversal symmetries. Among them, directional propagation of bulk magnons (i.e., quanta of spin wave excitation) is attracting much attention nowadays for its potentially large nonreciprocity suitable for spintronic and spin-caloritronic applications. Here, we demonstrate nonreciprocal propagation of spin waves for the conical spin helix state in Cu2OSeO3 due to a combination of dipole and Dzyaloshinskii-Moriya interactions. The observed nonreciprocal spin dispersion smoothly connects to the hitherto known magnetochiral nonreciprocity in the field-induced collinear spin state; thus, all the spin phases show diode characteristics in this chiral insulator.

Spectral dynamics of shift current in ferroelectric semiconductor SbSI.

Photoexcitation in solids brings about transitions of electrons/holes between different electronic bands. If the solid lacks an inversion symmetry, these electronic transitions support spontaneous photocurrent due to the geometric phase of the constituting electronic bands: the Berry connection. This photocurrent, termed shift current, is expected to emerge on the timescale of primary photoexcitation process. We observe ultrafast evolution of the shift current in a prototypical ferroelectric semiconductor antimony sulfur iodide (SbSI) by detecting emitted terahertz electromagnetic waves. By sweeping the excitation photon energy across the bandgap, ultrafast electron dynamics as a source of terahertz emission abruptly changes its nature, reflecting a contribution of Berry connection on interband optical transition. The shift excitation carries a net charge flow and is followed by a swing over of the electron cloud on a subpicosecond timescale. Understanding these substantive characters of the shift current with the help of first-principles calculation will pave the way for its application to ultrafast sensors and solar cells.

Preferential infiltration of interleukin-4-producing CXCR4+ T cells in the lesional muscle but not skin of patients with dermatomyositis.

Dermatomyositis (DM) and polymyositis (PM) are collectively termed autoimmune myopathy. To investigate the difference between muscle- and skin-infiltrating T cells and to address their role for myopathy, we characterized T cells that were directly expanded from the tissues. Enrolled into this study were 25 patients with DM and three patients with PM. Muscle and skin biopsied specimens were immersed in cRPMI medium supplemented with interleukin (IL)-2 and anti-CD3/CD28 antibody-conjugated microbeads. The expanded cells were subjected to flow cytometry to examine their phenotypes. We analysed the cytokine concentration in the culture supernatants from the expanded T cells and the frequencies of cytokine-bearing cells by intracellular staining. There was non-biased in-vitro expansion of tissue-infiltrating CD4(+) and CD8(+) T cells from the muscle and skin specimens. The majority of expanded T cells were chemokine receptor (CCR) type 7(-) CD45RO(+) effecter memory cells with various T cell receptor (TCR) Vßs. The skin-derived but not muscle-derived T cells expressed cutaneous lymphocyte antigen (CLA) and CCR10 and secreted large amounts of IL-17A, suggesting that T helper type 17 (Th17) cells may have a crucial role in the development of skin lesions. Notably, the frequency of IL-4-producing chemokine (C-X-C motif) receptor (CXCR)4(+) Th2 cells was significantly higher in the muscle-derived cells and correlated inversely with the serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) levels. stromal-derived factor (SDF)-1/CXCL12, a ligand for CXCR4, was expressed at a high level in the vascular endothelial cells between muscular fasciculi. Our study suggests that T cell populations in the muscle and skin are different, and the Th2 cell infiltrate in the muscle is associated with the low severity of myositis in DM.

Undercarboxylated osteocalcin is positively associated with free testosterone in male patients with type 2 diabetes mellitus.

UNLABELLED: Although a recent study showed that undercarboxylated osteocalcin (ucOC) is important for male fertility and testosterone production by testes, little is known about the relationship between ucOC and testosterone in humans. We found for the first time that ucOC is positively associated with free testosterone in men with type 2 diabetes. INTRODUCTION: The ucOC has been shown to play a key role in energy metabolism as an endocrine hormone. Although a recent animal study demonstrated that ucOC is also important for male fertility and testosterone production by the testes, association between serum osteocalcin and testosterone levels has not been understood in humans. METHODS: Sixty-nine male patients with type 2 diabetes were recruited and chemical bone markers [total osteocalcin (TOC), ucOC, bone-specific alkaline phosphatase (BAP), and urinary N-terminal cross-linked telopeptide of type I collagen (uNTX)], gonadotropic hormones [luteinizing hormone (LH) and follicle-stimulating hormone (FSH)], and free testosterone (FT) were measured. RESULTS: Multiple regression analysis showed that ucOC and ucOC/TOC ratio were associated positively with FT and negatively with LH (for ucOC, ß = 0.30, p = 0.042 and ß = -0.52, p = 0.048; for ucOC/TOC ratio, ß = 0.31, p = 0.031 and ß = -0.54, p = 0.036, respectively) independently of age, duration of diabetes, body mass index, and hemoglobin A1c. ucOC and ucOC/TOC ratio were significantly associated with FT even after adjusting for LH and FSH (ß = 0.24, p = 0.042 and ß = 0.25, p = 0.031, respectively). However, neither TOC, BAP, nor uNTX was associated with the gonadotropic hormones or FT levels. CONCLUSIONS: The present study indicates for the first time that ucOC is associated positively with FT and negatively with LH in type 2 diabetes. These findings support the recent evidence that ucOC is involved in testosterone production in male subjects.

Advanced glycation end products-induced vascular calcification is mediated by oxidative stress: functional roles of NAD(P)H-oxidase.

Vascular calcification, especially medial artery calcification, is associated with increased morbidity and mortality in patients with diabetes mellitus and end-stage kidney disease. Advanced glycation end products (AGEs) accumulated in these patients may be associated with vascular calcification, although their actions are obscure. Since AGEs can induce oxidative stress, which leads to vascular damage, we investigated an in vitro study to elucidate the effects of AGEs and the roles of NAD(P)H oxidase in the pathogenesis of vascular calcification. A7r5, rat vascular smooth muscle cells (VSMCs) were incubated in calcification medium with glycolaldehyde-derived AGE (AGE3) to measure calcium deposition and 8-hydroxydeoxyguanosine (8-OHdG) and to determine mRNA levels of osteopontin (OPN), osteocalcin (OCN), Runx2, Nox-1, Nox-4, and p22(phox) by real-time PCR. Calcium deposition was increased by AGE3 in a dose-dependent manner (100-300 µg/dl) in A7r5 cells. Expression levels of Runx2, OPN, and OCN mRNAs were significantly higher in AGE3 treatment than those in control BSA. Increased 8-OHdG concentration in the culture medium and higher expression of Nox-1, Nox-4, and p22(phox) mRNAs (3-6-fold) were observed in cells treated with AGE3. AGE3-stimulated calcium deposition was significantly decreased in the cells transfected by either small interfering RNA for Nox-4 or p22(phox), compared to the controls. In contrast, no significant effect was shown in silencing of Nox-1. Excessive oxidative stress and osteoblastic transition of VSMCs are involved in the pathogenesis of AGEs-induced vascular calcification. NAD(P)H oxidase plays important roles in this process.

Synthesis of the amino acid conjugates of epi-jasmonic acid.

The TES ether of the C6-hydroxy derivative of naturally occurring epi-jasmonic acid (epi-JA) was designed as epimerization-free equivalent of epi-JA. The TES ether was synthesized from (1R,4S)-4-hydroxycyclopent-2-enyl acetate in 13 steps. The acid part of the ether was activated with ClCO2Bui and subjected to condensation with L-amino acid at room temperature for 48 h. The TES group in the condensation product was removed in HCO2H (0°C, 30 min) and the resulting hydroxyl group was oxidized with Jones reagent (acetone, 0°C, 30 min) to furnish the amino acid conjugate of epi-JA. The amino acids examined are L-isoleucine, L-leucine, L-alanine, L-valine, and D-allo-isoleucine, which afforded the conjugates in 48-68% yields with 89-96% diastereomeric purity over the trans isomers. Similarly, the possible three stereoisomers of epi-JA were condensed with L-isoleucine successfully, producing the corresponding stereoisomers in good yields.

Effective plasma concentrations of mycophenolic acid and its glucuronide in systemic lupus erythematosus patients in the remission-maintenance phase.

WHAT IS KNOWN AND OBJECTIVE: Mycophenolate mofetil (MMF) has been reported recently to be effective in the treatment of systemic lupus erythematosus (SLE). The therapeutic range of mycophenolic acid (MPA) in SLE in the remission-maintenance phase remains to be clarified. The aim of this study was to evaluate the therapeutic efficacy of MMF and predose plasma concentrations of MPA and its phenolic glucuronide (MPAG) in patients with SLE in the remission-maintenance phase. METHODS: Thirty-one patients with SLE receiving a fixed dosage regimen of MMF (median and interquartile range, 1500 and 1000-2000mg/day) for at least 1month and who had not experienced any adverse drug reactions for more than 3months were enrolled. RESULTS: Significant improvement was observed after MMF administration in total haemolytic complement CH(50) and its fractions C3 and C4, immunoglobulins IgG, IgA and IgM, anti-dsDNA antibody, serum concentration of albumin and red blood cell count, even though the mean daily dose of prednisolone was significantly reduced (P=0·02). Median predose plasma concentrations of MPA and MPAG were 1·95 and 26·2µg/mL (interquartile ranges, 0·94-2·96 and 18·6-53·7 µg/mL). Predose plasma concentrations of MPA and MPAG correlated significantly with MMF dose (r=0·64, P<0·01 and r=0·39, P=0·03). WHAT IS NEW AND CONCLUSIONS: MMF improved clinical laboratory markers and reduced prednisolone dosage in SLE patients with predose plasma concentration of MPA and MPAG in the interquartile ranges of 0·94-2·96 and 18·6-53·7µg/mL, respectively.

Association between Inflammation and Functional Outcome in Patients with Sarcopenic Dysphagia.

OBJECTIVES: This study aimed to investigate whether inflammation affects the outcome of swallowing ability to improve treatment for sarcopenic dysphagia. DESIGN: A retrospective observational cohort study was performed using data from the Japanese sarcopenic dysphagia database. SETTING: The database was constructed using data from 19 hospitals and one home visiting rehabilitation team. PARTICIPANTS: Patients with sarcopenic dysphagia with measurements of C-reactive protein (CRP) and serum albumin (Alb) were included. MEASUREMENTS: Patients were assigned to two groups using CRP, Alb, and the Japanese modified Glasgow Prognostic Score (mGPS). The Food Intake LEVEL Scale (FILS) was measured at the times of admission and follow-up (FILS follow-up) to assess swallowing function. RESULTS: A total of 197 patients were included. Mean or median values of each parameter were as follows: age: 83.8±8.7, Alb: 3.2 ± 0.6 g/dL, CRP: 8.0 [3.0, 29.0] mg/L, mGPS: 1 [1-2], FILS: 7 [6-8], FILS follow-up: 8 [7-8], and duration of follow-up: 57.0 [27.0, 85.0] days. The FILS score at follow-up was significantly lower in the high CRP group (≥ 5.0 mg/L) than in the low CRP group (< 5.0 mg/L) (p = 0.01). Further, the FILS score at follow-up was significantly lower in the high mGPS group (class; 2) than in the low mGPS group (class; 0 and 1) (p = 0.03). In the multiple linear regression analyses without FILS at baseline, CRP and mGPS were independent risk factors for FILS follow-up. When FILS at baseline was entered, CRP and mGPS were not an independent risk factors for FILS follow-up. CONCLUSIONS: Inflammation could modify the outcome of the patients with sarcopenic dysphagia. Inflammation may be an important risk factor in evaluating patients with sarcopenic dysphagia.

Prevalence of Hoarseness and Its Association with Severity of Dysphagia in Patients with Sarcopenic Dysphagia.

OBJECTIVES: To investigate the prevalence of hoarseness and its association with the severity of dysphagia in patients with sarcopenic dysphagia. DESIGN: Cross-sectional study using the Japanese sarcopenic dysphagia database. SETTING: 19 hospitals including 9 acute care hospitals, 8 rehabilitation hospitals, 2 long-term care hospitals, and 1 home visit rehabilitation team. PARTICIPANTS: 287 patients with sarcopenic dysphagia, aged 20 years and older. MEASUREMENTS: Sarcopenic dysphagia was diagnosed using a reliable and validated diagnostic algorithm for the condition. The presence and characteristics of hoarseness classified as breathy, rough, asthenic, and strained were assessed. The prevalence of hoarseness and the relationship between hoarseness and Food Intake LEVEL Scale (FILS) were examined. Order logistic regression analysis adjusted for age, sex, naso-gastric tube, and handgrip strength was used to examine the relationship between hoarseness and FILS at baseline and at follow-up. RESULTS: The mean age was 83 ± 10 years. Seventy-four (26%) patients had hoarseness, while 32 (11%), 20 (7%), 22 (8%), and 0 (0%) patients had breathy, rough, asthenic, and strained hoarseness, respectively. Median FILS at the initial evaluation was 7 (interquartile range, 5-8). Hoarseness (ß=0.747, 95% confidence intervals= 0.229, 1.265, p=0.005), age, sex, naso-gastric tube, and handgrip strength were associated independently with baseline FILS, while hoarseness (ß=0.213, 95% confidence intervals= -0.324, 0.750, p=0.438) was not associated independently with the FILS at follow-up. CONCLUSIONS: Hoarseness was associated with the severity of dysphagia at baseline, however not a prognostic factor for sarcopenic dysphagia. Resistance training of swallowing and respiratory muscles and voice training as part of rehabilitation nutrition might be useful for treating sarcopenic dysphagia.

The Mass of Geniohyoid Muscle Is Associated with Maximum Tongue Pressure and Tongue Area in Patients with Sarcopenic Dysphagia.

OBJECTIVES: We investigated the associations about the mass of geniohyoid and tongue muscle and the maximum tongue pressure in patients with sarcopenic dysphagia using ultrasonography. DESIGN: Cross sectional study. SETTING: 5 hospitals including 3 acute and 2 rehabilitation hospitals and 1 older facility. PARTICIPANTS: 36 inpatients with sarcopenic dysphagia. MEASUREMENTS: Ultrasonography was performed for geniohyoid muscle and tongue. The area for geniohyoid and tongue muscles in sagittal plane and the mean brightness level (0-255) in the muscle area were calculated. Maximum tongue pressure as strength of swallowing muscle were investigated. Partial correlation coefficient and multiple regression analysis adjusting for age and sex were performed. RESULTS: The mean age was 81.1 ± 7.9. Men were 23. The mean BMI was 19.0 ± 4.1. The mean maximum tongue pressure was 21.3 ± 9.3 kPa. The mean cross sectional area for geniohyoid muscles was 140 ± 47 mm2. The mean brightness for geniohyoid muscle was 18.6 ± 9.0. The mean cross sectional area for tongue muscles was 1664.1 ± 386.0 mm2. The mean brightness for tongue muscles was 34.1 ± 10.6. There was a significant positive correlation between area of geniohyoid muscle and maximum tongue pressure (r = 0.38, p = 0.04). Geniohyoid muscle area was an explanatory factor for maximum tongue pressure (p = 0.012) and tongue muscle area (p = 0.031) in multivariate analysis. CONCLUSIONS: Geniohyoid muscle mass was an independent explanatory factor for maximum tongue pressure and tongue muscle mass.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime.

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

Enhanced biofilm formation and 3-chlorobenzoate degrading activity by the bacterial consortium of Burkholderia sp. NK8 and Pseudomonas aeruginosa PAO1.

AIMS: To characterize biofilm formation of a chlorobenzoates (CBs) degrading bacterium, Burkholderia sp. NK8, with another bacterial species, and the biodegradation activity against CBs in the mixed-species biofilm. METHODS AND RESULTS: Burkholderia sp. NK8 was solely or co-cultured with each of five other representative bacteria in microtitre dishes. Biofilm formation involving the strain NK8 was synergistically promoted by co-culturing with only Pseudomonas aeruginosa PAO1. Epifluorescent microscopy revealed that cells of the bacterial strain NK8 were viable and distributed randomly in the mixed-species biofilms. Enumeration of the attached cells on the surface of wells revealed that cells of the strain NK8 increased approx. 10-fold by the co-culture with the strain PAO1 compared to those by monoculture of the strain NK8, and the degradation activity of 3-chlorobenzoate by the dual-species biofilms was more promoted than that by the strain NK8-monocultured biofilms. CONCLUSIONS: Enhanced biofilm formation of Burkholderia sp. NK8 by the bacterial consortium occurred, but is determined by the partner bacterial species. The mixed-species biofilms have the advantage to degrade CBs on a solid surface. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides a significance of bacterial consortia on the biofilm formation and the degradation activity of Burkholderia sp. NK8, which contribute for complete degradation of chlorinated aromatics.

An improved method to extract RNA from soil with efficient removal of humic acids.

AIMS: To remove humic substances from RNA extracted from soil for the study of bacterial gene expression in soil. METHODS AND RESULTS: A soil RNA extraction method was improved by optimization of lysis conditions and further purification by a spin column, to efficiently remove humic substances that may hinder enzymatic reactions of extracted RNA. Fluorescence spectrophotometry demonstrated that the improved method removed both humic and fulvic acids efficiently. Using the improved method, the signal of gene expression detected by real-time reverse transcription-polymerase chain reaction (RT-PCR) increased 10-fold compared with that using the previous method. Using the method, we extracted RNA from a sterilized field soil, which was inoculated with Pseudomonas putida KT2440 transformed with a chloroaromatic degrading plasmid, in the presence or absence of 3-chlorobenzoate (3CB). Real-time RT-PCR performed using the extracted RNA as a template confirmed the induction of chloroaromatic degrading genes in 3CB-amended soil. CONCLUSIONS: The modified soil RNA extraction method succeeded in removing the co-extracted humic substances from soil RNA efficiently and improving the detection efficiency of the bacterial gene expression in soil. SIGNIFICANCE AND IMPACT OF THE STUDY: This improved method is a useful tool for the extraction of RNA to detect gene expression in soil.

The influence of brain death on tissue factor expression in the pancreatic tissues and isolated islets in rats.

INTRODUCTION: Tissue factor (TF) in islets has been identified as the main trigger of the instant blood-mediated inflammatory reaction. Because the crucial events that directly induce TF remain to be determined, we focused on the influence of brain death (BD) on TF expression in pancreatic tissues and isolated islets. MATERIALS AND METHODS: BD was induced in male Lewis rats weighing 250-300 g by inflation of a Fogarty catheter placed intracranially. The rats were mechanically ventilated for 6 hours until removal of the pancreas. The expression of TF protein in pancreatic tissues was examined using Western blotting assay. Messenger RNA (mRNA) expressions of TF in pancreatic tissue and isolated islets were analyzed using real-time polymerase chain reaction (PCR) assay. The influence of BD on the isolation outcome was evaluated by islet yield, purity, viability, and function. RESULTS: TF protein and mRNA levels in the pancreatic tissues were similar between the groups. However, TF mRNA in the isolated islets of the BD group was significantly greater than that of the control group (P = .04). Islet yield was considerably lower, and purity significantly lower in the BD than the control group (P = .002). Unexpectedly, ATP/DNA ratio and respiratory activity were comparable between the groups. CONCLUSIONS: Although BD per se was not sufficient to induce TF expression in pancreatic tissues, BD combined with subsequent warm ischemic damage during isolation procedures remarkably up-regulated TF expression in isolated islets, suggesting that BD is of great importance as an initiator of TF induction in the islet grafts. The present study demonstrated that the expression of inflammatory mediators rather than islet viability is more susceptible to BD.

C5a inhibitory peptide combined with gabexate mesilate is a clinically available candidate for preventing the instant blood-mediated inflammatory reaction.

BACKGROUND: The instant blood-mediated inflammatory reaction, characterized by activation of both the coagulation and complement cascades, is a serious obstacle to successful islet engraftment. No attractive protocol is clinically available as yet. The objective of the present study was to examine whether complementary peptide against an active region of C5a in combination with a clinically available anticoagulant could provide an effective protocol for suppression of the instant blood-mediated inflammatory reaction. METHODS: Three islet equivalents per gram of syngeneic rat grafts were transplanted intraportally into 6 pairs of rats with streptozotocin-induced diabetes. Islets from the same donor were transplanted into each pair. In each pair, one rat was treated with C5a inhibitory peptide in addition to continuous intravenous infusion of gabexate mesilate and the other rat, injected with equivalent amount of saline solution, served as the control. In addition, 6 rats that received transplants from irrelevant donors were treated with the same dose of gabexate mesilate. We evaluated the cure rate, time to normoglycemia, liver insulin concentration in recipients, and results of in vivo glucose tolerance tests. RESULTS: The cure rate was remarkably improved and the time to normoglycemia in cured animals was significantly shortened with C5a inhibitor plus gabexate treatment. In six rats that received only gabexate mesilate, normoglycemia was not restored during the study. CONCLUSIONS: These data suggest that C5a inhibitory peptide combined with gabexate mesilate could be an attractive drug candidate without adverse effects to control the detrimental innate immune responses induced in clinical islet transplantation.

Superiority of fresh islets compared with cultured islets.

INTRODUCTION: It has recently been reported that the outcomes of islet transplantation with short periods of culture are comparable with those of freshly isolated islets. To clarify the influence of culture, fresh islets were compared with cultured islets in terms of quality. MATERIALS AND METHODS: The quality of freshly isolated islets was compared with that of cultured islets with CMRL 1066 including 10% allogeneic serum, CMRL 1066 including 0.5% human serum albumin, or Miami medium. We evaluated static glucose stimulation tests, insulin/DNA contents, ADP/ATP ratios, and an intraportal transplantation model into syngeneic diabetic rats. The expression of inflammatory mediators in the islets was examined using Western blotting for tissue factor (TF), which is the initiator of detrimental instant, blood-mediated, inflammatory reactions (IBMIR). RESULTS: Although the survival rate was similar in all groups, the stimulation index upon glucose challenge and the insulin/DNA ratio were significantly higher among fresh islets. Most importantly, the expression of TF on islets was significantly lower in fresh islets, suggesting that culture enhanced TF-dependent IBMIR after transplantation. In an in vivo transplantation model, the curative rate and insulin production by the recipient liver was considerably greater in the fresh islet group. CONCLUSIONS: Isolated islets without prior culture showed results superior to cultured islets.

A novel predictive method for assessing the quality of isolated pancreatic islets using scanning electrochemical microscopy.

INTRODUCTION: The current methods for evaluating islet potency are not useful in clinical transplantation. Therefore, we need reliable, rapid methods enabling accurate prediction of islet quality. MATERIALS AND METHODS: We evaluated respiratory activity using scanning electrochemical microscopy (SECM), glucose-stimulated respiratory activity, glucose-stimulated insulin release, ADP/ATP assays, insulin/DNA levels, and Trypan blue exclusion tests as predictive methods for the ability of isolated rat islets to cure syngeneic diabetic rats. RESULTS: Although glucose-stimulated respiratory activity, basal respiratory activity, ADP/ATP ratio, and glucose-stimulated insulin release were significantly correlated with the outcome of transplantation into diabetic rats, there was no correlation between outcomes, insulin/DNA ratios, and Trypan blue exclusion tests. The glucose-stimulated respiratory activity in islet preparations that could cure diabetic rats was significantly greater than those unable to cure diabetes. Rat islets with >1.5-fold glucose-stimulated respiratory activity consistently cured diabetic rats, whereas those with a value <1.5 hardly cured any rats. CONCLUSION: Measurement of the glucose-stimulated respiratory activity using SECM technique is a novel method that may be useful as a rapid, potent predictor of the outcome of clinical islet transplantation.

Efficient recycling of nutrients in modern and past hypersaline environments.

The biogeochemistry of hypersaline environments is strongly influenced by changes in biological processes and physicochemical parameters. Although massive evaporation events have occurred repeatedly throughout Earth history, their biogeochemical cycles and global impact remain poorly understood. Here, we provide the first nitrogen isotopic data for nutrients and chloropigments from modern shallow hypersaline environments (solar salterns, Trapani, Italy) and apply the obtained insights to δ15N signatures of the Messinian salinity crisis (MSC) in the late Miocene. Concentrations and δ15N of chlorophyll a, bacteriochlorophyll a, nitrate, and ammonium in benthic microbial mats indicate that inhibition of nitrification suppresses denitrification and anammox, resulting in efficient ammonium recycling within the mats and high primary productivity. We also suggest that the release of 15N-depleted NH3(gas) with increasing salinity enriches ammonium 15N in surface brine (≈34.0‰). Such elevated δ15N is also recorded in geoporphyrins isolated from sediments of the MSC peak (≈20‰), reflecting ammonium supply sufficient for sustaining phototrophic primary production. We propose that efficient nutrient supply combined with frequent bottom-water anoxia and capping of organic-rich sediments by evaporites of the Mediterranean MSC could have contributed to atmospheric CO2 reduction during the late Miocene.

Crystal structure of an anhydrous form of trehalose: structure of water channels of trehalose polymorphism.

alpha, alpha-Trehalose (trehalose) is a nonreducing disaccharide of glucose and is accumulated at high concentrations in some anhydrobiotic organisms, which can survive without water for long periods and rapidly resume active metabolism upon hydration. Although it has been proposed that the intriguing mechanism of bioprotection in anhydrobiosis is conferred by a water channel, details of such a channel have yet to be revealed. We determined the crystal structure of a trehalose anhydrate to further understand the relationship between the structure of water channels and the trehalose polymorph. The space group was identical to that of the dihydrate and the lattice constants were also very similar. Among the five intermolecular hydrogen bonds between the trehalose molecules, four were preserved in the anhydrate. If dehydration of the dihydrate is slow and/or gentle enough to preserve the hydrogen bonds, transformation from the dihydrate to the anhydrate may occur. There are two different holes, hole-1 and hole-2, along one crystal axis. Hole-1 is constructed by trehalose molecules with a screw diad at its center, while hole-2 has a smaller diameter and is without a symmetry operator. Because of the screw axis at the center of hole-1, hollows are present at the side of the hole with diameters roughly equal to that of hole-1. Hole-1 and side pockets followed by hollows correspond to the positions of two water molecules of the dihydrate. The side hollows of the water channel are also observed in the water-filled hole of the dihydrate. Consequently, hole-1 is considered to be a one-dimensional water channel with side pockets. We also calculated molecular and crystal energies to examine the rapid water uptake of the anhydrate. It was demonstrated that the intermolecular interactions in the anhydrate were weaker than in the other anhydrous form, and probably also than those in amorphous trehalose. The anhydrate provides water capture for another solid form and gives protection from water uptake. These structural properties of the anhydrate may elucidate bioprotection in anhydrobiosis.

Influence of a current style of culture on the quality of isolated pancreatic islets.

OBJECTIVE: Comparable outcomes of islet transplantation with short periods of culture may be achieved with various culture media. To clarify the influence of a style of culture on isolated pancreatic islets, islet quality of fresh islets was compared with those cultured in several different fashions including not only for viability but also for inflammatory mediators. MATERIALS AND METHODS: Wistar rat islets were cultured for 48 hours with CMRL including 10% allogeneic serum; CMRL including 0.5% human serum albumin (HSA); and Miami medium including 0.5% HSA. The influence of culture conditions on islet integrity was evaluated by survival rate of islets during culture and visual scoring. The influence of culture conditions on islet function and viability was examined by ADP/ATP tests, insulin/DNA content, and glucose stimulation tests. RESULTS: Although the survival rates were similar for all groups, the visual scoring was lower in Miami medium. The stimulation index in glucose challenge tests was higher for fresh islets than the media (P = .02). Insulin/DNA ratios revealed the same tendency as glucose challenge tests (P = .0005). ADP/ATP ratio was lower in both the fresh and serum groups than in the others (P = .38), suggesting that apoptotic islets are relatively fewer in both fresh and serum groups. Most importantly, the expression of tissue factor (TF) on the islets was considerably lower in the fresh group, suggesting that a current style of culture could enhance TF-dependent instant blood-mediated inflammatory reactions after transplantation. CONCLUSION: In conclusion, Isolated islets without prior culture shows characteristics beneficial for transplantation using current modes of culture.