Barents-Kara sea-ice decline attributed to surface warming in the Gulf Stream.

Decline in winter sea-ice concentration (SIC) in the Barents-Kara Sea significantly impacts climate through increased heat release to the atmosphere. However, the past Barents-Kara SIC decrease rate is underestimated in the majority of Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models. Here we show that climate model simulations can reproduce the Barents-Kara SIC trend for 1970-2017 when sea surface temperature (SST) variability in the Gulf Stream region is constrained by observations. The constrained warming of the Gulf Stream strengthens ocean heat transport to the Barents-Kara Sea that enhances the SIC decline. The linear trends between the SIC and SST are highly correlated in the CMIP6 ensemble, suggesting that the externally forced component of the Gulf Stream SST increase explains up to 56% of the forced Barents-Kara SIC trend. Therefore, future warming of the Gulf Stream can be an essential pacemaker of the SIC decline.

1.8 µm band broadband hybrid light source employing a combination of a super luminescent diode and thulium-doped fiber amplifier.

We have proposed a broadband hybrid light source that combines a super luminescent diode (SLD) and thulium-doped fiber amplifier (TDFA) and operates in the 1.8 µm band. This light source can improve the characteristics of the output spectrum by amplifying the output light of the SLD with TDFA. In this study, we investigate the dependence of the output spectral characteristics of the hybrid broadband light source on the thulium-doped fiber (TDF) length used in the TDFA as well as the output spectra of three newly developed SLDs of 1660, 1690, and 1730 nm bands. In the evaluation of the output bandwidth, there are various definitions of output bandwidth, but we adopted the bandwidth with power density of over -40dBm/0.1nm. This is because it is possible to evaluate in this band with a dynamic range of "30 dB/0.1 nm" by using a general optical spectrum analyzer. The hybrid light source achieves the bandwidth of 332 nm, from 1579 to 1911 nm, and a high total output power of over 15 dBm. The maximum ripple was less than ∼0.1dB, which is similar to the maximum value of that of the SLD, without any deterioration in the ripple characteristics owing to the hybrid configuration of the SLD and TDFA.

CuI-Catalyzed Coupling Reactions of 4-Iodopyrazoles and Alcohols: Application toward Withasomnine and Homologs.

The direct 4-alkoxylation of 4-iodo-1H-pyrazoles with alcohols was achieved by a CuI-catalyzed coupling protocol. The optimal reaction conditions employed excess alcohol and potassium t-butoxide (2 equiv) in the presence of CuI (20 mol%) and 3,4,7,8-tetramethyl-1,10-phenanthroline (20 mol%) at 130 °C for 1 h under microwave irradiation. The present method was efficiently applied to the synthesis of withasomnine and its six- and seven-membered cyclic homologs.

Clearance Gap: Does It Really Matter for the Evaluation of Vascular Access Function?

BACKGROUNDS: Vascular access (VA) stenosis increases the risk of VA obstruction due to the gradual progress of intimal thickening. Therefore, we should try to detect VA stenosis early. However, we do not have a cutoff for when a difference between prescribed Kt/V and delivered Kt/V reflects a clinical issue. Thus, we have devised a new index, the 'clearance gap' (CL-Gap), which quantifies the difference between the effective clearance (eCL) of a hemodialysis (HD) patient and the theoretical clearance (tCL) of a dialyzer to detect a decrease in dialysis efficiency due to VA dysfunction. SUMMARY: We propose a qualitative technique of analyzing dialysis (the CL-Gap method) concerning Kt/V by estimating the eCL based on the delivered Kt/V and the difference with the tCL based on the dialyzer. When VA recirculation and blood removal failure occurs, the eCL decreases, and it is expected that the CL-Gap increases. On the contrary, if uniform internal removal occurs, the eCL rises when we overestimate the delivered Kt/V and the CL-Gap is expected to decrease. However, we cannot judge whether a high CL-Gap indicates VA dysfunction immediately because it is necessary to consider not only VA dysfunction, but also the effect of other factors on the CL-Gap. Key Messages: We believe that it is important to think about VA function in a qualitative manner when managing the dose using the CL-Gap to achieve better dialysis treatment.

Additional Arctic observations improve weather and sea-ice forecasts for the Northern Sea Route.

During ice-free periods, the Northern Sea Route (NSR) could be an attractive shipping route. The decline in Arctic sea-ice extent, however, could be associated with an increase in the frequency of the causes of severe weather phenomena, and high wind-driven waves and the advection of sea ice could make ship navigation along the NSR difficult. Accurate forecasts of weather and sea ice are desirable for safe navigation, but large uncertainties exist in current forecasts, partly owing to the sparse observational network over the Arctic Ocean. Here, we show that the incorporation of additional Arctic observations improves the initial analysis and enhances the skill of weather and sea-ice forecasts, the application of which has socioeconomic benefits. Comparison of 63-member ensemble atmospheric forecasts, using different initial data sets, revealed that additional Arctic radiosonde observations were useful for predicting a persistent strong wind event. The sea-ice forecast, initialised by the wind fields that included the effects of the observations, skilfully predicted rapid wind-driven sea-ice advection along the NSR.

A numerical study on the seasonal variability of polychlorinated biphenyls from the atmosphere in the East China Sea.

A three-dimensional/high-resolution transport model for persistent organic pollutants (POPs) has been developed for the East China Sea (ECS). The POPs model has four compartments (gaseous, dissolved, phytoplankton-bound, and detritus-bound phases) and includes processes for diffusive air-water exchange, phytoplankton uptake/depuration to POPs, decomposition of dissolved phase, vertical sinking of phytoplankton, detritus production by phytoplankton mortality, and vertical sinking and decomposition of detritus. The POPs model is coupled with an ocean circulation model that can reproduce the seasonal variation in physical variables to represent the advection and diffusion of POPs. We applied the POPs model to the polychlorinated biphenyl congener 153 (PCB 153) from the atmosphere and examined the behavior of PCB 153 in the ocean. The model showed a remarkable seasonal variability of PCB 153. Concentrations in the dissolved and particulate phases are high in winter (January-March) and low in summer (July-September). In coastal regions, where chlorophyll a concentration is high, horizontal and vertical distributions in the dissolved and particulate PCB 153 concentrations are strongly affected by phytoplankton uptake. The sensitivity experiments on the dynamics of PCB 153 suggested that a change of Henry's law constant associated with water temperature is the major factor controlling the seasonal variability of PCB 153. The model-based yearly mass balance of PCB 153 in the ECS indicated that most of the atmospheric input (35.5 kg year(-1)) is removed by the horizontal advection outside the ECS (19.0 kg year(-1)) and accumulates to the sea bottom by vertical sinking (15.7 kg year(-1)). For comparison with PCB 153, we also conducted simulations for PCB 52, 101, and 180. The seasonal variations are similar to that of PCB 153. The mass balance of PCB 52 that has short half-life time and less hydrophobic property shows the different results compared with PCB 101, 153, and 180.

Age-associated increases in poor outcomes after traumatic brain injury: a report from the Japan Neurotrauma Data Bank.

Age is an important factor influencing outcome after severe traumatic brain injury (TBI). In general, the older the victim, the higher the probability of a poor outcome. To investigate the mechanism underlying the link between age and outcome, the data for 797 patients enrolled in the Japan Neurotrauma Data Bank (JNTDB), aged 6 years or older, with Glasgow Coma Scale (GCS) scores of 8 or less on admission or deterioration to that level within 48 h of impact were analyzed. Thirty-eight percent of the patients were between the ages of 40 and 69 years, and 24% of the patients were older than 69 years. Older patients had higher rates of mortality and lower rates of favorable outcome. The frequency of mass lesions which were associated with poorer outcomes significantly increased with age, but regardless of the intracranial lesion type, older patients had poorer outcomes. The GCS score and the occurrence of systemic complications did not differ significantly according to age. Multiple systemic injury was less frequent in older patients. The varied occurrence of intracranial lesion types according to age is likely caused by the disparity between the young and aged brain in the progression of secondary brain injury. Alteration in the pathophysiological response, which is related to the development of secondary brain injury in the aging brain, probably contributes to more severe and irreversible brain damage in older patients, and is thus associated with poor outcomes.

Final report of the Japan Neurotrauma Data Bank project 1998-2001: 1,002 cases of traumatic brain injury.

A 4-year study (Japan Neurotrauma Data Bank) of the medical treatment of 1002 cases of traumatic brain injuries in Japan was conducted from 1998 to 2001 at 10 emergency medical centers. Patients with severe head injury were eligible for entry with a Glasgow Coma Scale score of 8 or less at admission. Patients who underwent craniotomy were also included. Children under 5 years old were excluded. An original data sheet with 392 items from multi-focal viewpoints, such as etiology of injury, pre-hospital care, initial treatment including neuro-intensive care unit, and surgical treatment, was created. The results show that the patient's age and mechanism of injury are the most important factors in the outcome.

Molecular and immunohistochemical studies in expression of voltage-dependent Ca2+ channels in dorsal root ganglia from streptozotocin-induced diabetic mice.

We have recently demonstrated that intrathecal injection of a selective P/Q-type blocker of the voltage-dependent Ca(2+) channels (VDCCs) significantly inhibited the mechanical hyperalgesia in streptozotocin (STZ)-induced diabetic mice, its antinociceptive effect being greater than in controls. In this study, to further clarify the underlying mechanism of the STZ-induced hyperalgesia, we investigated the expression level of the VDCC alpha1A and alpha1B subunits in the dorsal root ganglia (DRGs) and the dorsal spinal cord under this hyperalgesia. Real-time PCR analysis showed mRNA expression of alpha1A (P/Q-type), but not alpha1B (N-type), was significantly increased in the DRGs from the STZ-induced diabetic mice. On the other hand, gene expression of both alpha1 subunits was not changed in the dorsal part of the spinal cord. In diabetic DRG neurons, the number of large nerve cells was significantly reduced, whereas small neurons were significantly increased. Immunohistochemical study demonstrated the alpha1A-positive neurons, but not alpha1B-positive neurons, increased significantly greater in diabetic DRGs than in control in all cell size. These results indicate that an alteration in expression of P/Q-type VDCCs, especially in the small and medium-diameter primary afferent fibers, in pain pathways ascending input to the spinal cord may be involved in hypersensitivity in STZ-induced diabetes.

Effects of aging and HIF-1alpha deficiency on permeability of hippocampal vessels.

We examined age-related changes in the blood-brain barrier (BBB) of neural cell-specific hypoxia inducible factor-1alpha (HIF-1alpha) deficient mice, which showed hydrocephalus with neuronal cell loss, to investigate an effect of neural cell-specific HIF-1alpha deficiency or hydrocephalus on vascular function. Vascular permeability of horseradish peroxidase (HRP) and binding of cationized ferritin (CF) particles to the endothelial cell luminal surface, as a marker of glycocalyx, were investigated. The thickness of CF-labeled glycocalyx was significantly decreased in the cortex in mutant mice compared with that of control mice, although it was not paralleled by increased vascular permeability. In addition, strong staining for HRP was seen around vessels located along the hippocampal fissure in 24-month-old mutant mice. The reaction product of HRP appeared in an increasing number of the endothelial cell abluminal vesicles and within the thickened basal lamina of arterioles in the hippocampus, showing increased vascular permeability. There were no leaky vessels in 10-week-old mutant mice or 10-week-old and 24-month-old control mice. These findings suggest the necessity of two factors, aging and hydrocephalus, for BBB dysfunction in HIF-1alpha deficient mice.

Successful selective intra-arterial thrombolytic therapy for embolic stroke in a patient with asplenia syndrome and unrepaired cyanotic congenital heart disease.

We report successful selective local intra-arterial thrombolytic therapy for thromboembolic occlusion of right middle cerebral artery in a patient with asplenia syndrome and unrepaired cyanotic congenital heart disease.

Systemic nitric oxide production rate during hemodialysis and its relationship with nitric oxide-related factors.

BACKGROUND/AIMS: Nitric oxide (NO) plays a key role in the regulation of vascular tone and controls both local and systemic hemodynamics. Here, we estimated systemic NO production rates of hemodialysis (HD) patients, based on the time course of plasma concentration of nitrate (an oxidative end product of NO) and investigated possible roles of NO-related factors. METHODS: We measured plasma concentrations of nitrate, L-arginine (a substrate of NO synthase: NOS), asymmetric dimethylarginine (ADMA, an endogenous NOS inhibitor), tetrahydrobiopterin (BH4, a NOS cofactor), dihydrobiopterin (BH2, an oxidized form of BH4) and oxidized low-density lipoprotein (oxyLDL; an index of oxidative stress) before and after 30-min and 4-hour HD (n = 10). RESULTS: The time-averaged NO production rate during HD was estimated by fitting the time course of plasma nitrate concentration with a single-compartment model (4.00 +/- 0.82 micromol/min, 4.99 +/- 1.08 micromol/kg/h). The L-arginine/ADMA ratio (L-arginine availability) after 30-min HD showed a positive correlation with the NO production rate (p < 0.05). CONCLUSION: The systemic NO production rate during HD could be estimated by the single-compartment analysis. The L-arginine/ADMA ratio seems to play an important role in the regulation of the NO production during HD.

A new class of type I protein geranylgeranyltransferase (GGTase I) inhibitor.

Replacement of the thiol groups in 1, a potent and highly selective Candida albicans GGTase I inhibitor discovered through screening, with an imidazole ring was achieved by using solid phase synthesis. A non-thiol compound, 7, was found as a representative of a new class of potent C. albicans GGTase I inhibitor with high selectivity against human GGTase I.

Epidemiology, prevention and countermeasures against severe traumatic brain injury in Japan and abroad.

On the basis of accurate statistical reports in regard to traffic accidents and safety in Japan, it is clear that traffic accidents on the road, injured victims and all other losses due to these accidents have been increasing since around 1980. Nevertheless, the number of deaths due to traffic accidents has been gradually declining over the last six years. More detailed analysis of data revealed that the most significant factor for the recent reduction of traffic accident deaths was the marked reduction of deaths related to head injury. From the neurosurgical viewpont, the Japanese Data Bank Committee for Traumatic Brain Injury began its formal activity in 1998. Although the registered number of severe head injuries is statistically too small at present to arrive at conclusions, some interesting points draw our attention. As for intracranial pathology diagnosed by the image of cranial CT scans, two thirds of nontraffic cases have focal brain lesions alone. On the other hand, in traffic cases one third of patients have focal lesions alone and one fourth have diffuse brain lesion exclusively. In this study, in 23% of traffic accidents and 12% of nontraffic accidents, consumption of alcohol led indirectly to head injuries. The schedule and details of countermeasures taken against traffic accidents are discussed from an international viewpoint.