Giant adiabatic temperature change and its direct measurement of a barocaloric effect in a charge-transfer solid.

Solid refrigerants exhibiting a caloric effect upon applying external stimuli are receiving attention as one of the next-generation refrigeration technologies. Herein, we report a new inorganic refrigerant, rubidium cyano-bridged manganese-iron-cobalt ternary metal assembly (cyano-RbMnFeCo). Cyano-RbMnFeCo shows a reversible barocaloric effect with large reversible adiabatic temperature changes of 74 K (from 57 °C to -17 °C) at 340 MPa, and 85 K (from 88 °C to 3 °C) at 560 MPa. Such large reversible adiabatic temperature changes have yet to be reported among caloric effects in solid-solid phase transition refrigerants. The reversible refrigerant capacity is 26000 J kg-1 and the temperature window is 142 K. Additionally, cyano-RbMnFeCo shows barocaloric effects even at low pressures, e.g., reversible adiabatic temperature change is 21 K at 90 MPa. Furthermore, direct measurement of the temperature change using a thermocouple shows +44 K by applying pressure. The temperature increase and decrease upon pressure application and release are repeated over 100 cycles without any degradation of the performance. This material series also possesses a high thermal conductivity value of 20.4 W m-1 K-1. The present barocaloric material may realize a high-efficiency solid refrigerant.

Second Percutaneous Transluminal Angioplasty Versus Surgical Reconstruction for Hemodialysis Access Failure Within a Short Time Period.

BACKGROUND: The purpose of this study was to compare patency and nonabandonment rates for second percutaneous transluminal angioplasty (PTA) and surgical reconstruction for the treatment of failing vascular access due to restenosis or reocclusion in a short time after initial PTA. METHODS: Seventy two consecutive patients who underwent second treatment within 90 days after the initial PTA were evaluated retrospectively. The patency (time to corrective procedure) and access abandonment were compared among patients who underwent a second PTA (n = 35) and those who underwent surgical reconstruction (n = 37). Univariate and multivariate analyses were performed to determine independent predictors of patency and access abandonment at 1 year after the treatment. RESULTS: At 1 year after the treatment, the patency rates were 35.1% and 11.4% (P = 0.02) and nonabandonment rates were 64.9% and 77.1% (P = 0.25) for surgical reconstruction and second PTA, respectively. The Kaplan-Meier survival analysis showed that the surgical reconstruction group had better patency probability (P = 0.02), but there was no difference in the nonabandonment probability between the groups (P = 0.29). Shorter time to retreatment was associated with good patency. The female gender was likely to be associated with access abandonment. CONCLUSIONS: The access abandonment between the 2 procedures had no difference, although surgical reconstruction provided better patency than second PTA.

Pressure-induced evolution in the durability of nickel-metal hydride batteries under high-current charge.

We found that an AAA-type battery (min. 750 mAh) pressurized with Ar or N2 at pressures of up to 5 MPa exhibited a significant durability enhancement even under high-current conditions. As an example of a charge-discharge cycle test at 3 amperes, the residual ratio of capacity at atmospheric pressure decreased to approximately 90% of the standard capacity before 50 cycles. However, at a pressure of 3 MPa of N2, the capacity remained at more than 90% until 180 cycles. With an increase in the pressure, the residual ratio of capacity was further improved. It has been considered that, at the positive electrode of the Ni-MH battery, the chemical reaction from nickel(II) hydroxide (Ni(OH)2) crystals to nickel oxide hydroxide (NiOOH) crystals occurs during the charging process. However, X-ray diffraction (XRD) results in the present study do not support this solid-solid reaction between these two types of crystal. To address this contradiction, we propose a different reaction mechanism by introducing the concept of non-crystalline fine particles of compounds, which are undetected by XRD. This mechanism clearly explains how the pressure affects the durability improvement. Pressurized batteries, which are capable of fast charge-discharge operation under high-current conditions, can provide a new route for application fields of unconventional energy storage.

Long-term prognostic value of the combined assessment of clinical and computed tomography findings in type: An acute aortic dissection.

Type A acute aortic dissection (TAAAD) carries a high mortality rate in the absence of surgical treatment. This study sought to determine whether combining the assessment of clinical and computed tomography (CT) findings can be used to predict the long-term all-cause mortality rate of patients with TAAAD.Eighty-five consecutive patients with TAAAD who had undergone CT imaging and surgery were retrospectively reviewed. For the clinical and CT findings, univariate testing followed by multivariate logistic regression analysis was conducted to identify independent predictors of death. Then, the area under the receiver operating characteristic curve of the combined prediction model was calculated.The long-term mortality rate was 34.1% in our cohort (a median follow-up period of 60 months). Multivariate logistic regression analysis identified the following presenting variables as predictors of death: male sex (odds ratio [OR]: 6.67; 95% confidence interval [CI]: 1.67-25.0; P = .007), kidney malperfusion (OR: 2.18; 95% CI: 1.16-4.1; P = .02), and descending aorta size (OR: 1.12; 95% CI: 1.00-1.25; P = .05). Receiver operating characteristic curve analysis revealed an area under the receiver operating characteristic curve of 0.84 when using the combined model for prediction of long-term all-cause mortality (P ≤ .01).The combined assessment of clinical and CT findings can reasonably predict the long-term prognosis of TAAAD with surgery.

Perfusion abnormality on three-dimensional arterial spin labeling in patients with acute encephalopathy with biphasic seizures and late reduced diffusion.

PURPOSE: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common encephalopathy subtype in Japanese children. Few case reports have shown perfusion abnormality on arterial spin labeling (ASL) in patients with AESD. The present study aimed to review the chronological change of cerebral perfusion on three-dimensional (3D) ASL in patients with AESD. METHODS: Twenty consecutive patients with AESD were enrolled; the patients underwent MRI including 3D ASL. The clinical course of AESD was divided into four phases according to the time from occurrence of seizures to MRI. Two neuroradiologists independently assessed presence or absence, distribution, and severity of perfusion abnormality using ASL and qualitatively scored perfusion abnormality using a five-point grading system. The level of interobserver agreement in the evaluation was analyzed using weighted κ statistics. Additionally, the signal ratio of abnormal perfusion region and peri-central sulcus region on ASL was semi-quantitatively evaluated. Moreover, we qualitatively compared the distribution between perfusion abnormality on ASL and bright tree appearance (BTA) on diffusion-weighted image (DWI). RESULTS: ASL showed hypoperfusion from 8.5 to 22 h after early seizures (ESs) and hyperperfusion within 24 h after late seizures (LSs). Various perfusions were found >3 days after LSs. Interobserver agreement for qualitative scored perfusion abnormality was good (κ = 0.77). The distribution of abnormal perfusion was relatively consistent with BTA. CONCLUSION: In AESD, cerebral perfusion changes with time. ASL showed hypoperfusion from 8.5 to 22 h after ESs, hyperperfusion within 24 h after LSs in patients with AESD.

Colossal barocaloric effects in plastic crystals.

Refrigeration is of vital importance for modern society-for example, for food storage and air conditioning-and 25 to 30 per cent of the world's electricity is consumed for refrigeration1. Current refrigeration technology mostly involves the conventional vapour compression cycle, but the materials used in this technology are of growing environmental concern because of their large global warming potential2. As a promising alternative, refrigeration technologies based on solid-state caloric effects have been attracting attention in recent decades3-5. However, their application is restricted by the limited performance of current caloric materials, owing to small isothermal entropy changes and large driving magnetic fields. Here we report colossal barocaloric effects (CBCEs) (barocaloric effects are cooling effects of pressure-induced phase transitions) in a class of disordered solids called plastic crystals. The obtained entropy changes in a representative plastic crystal, neopentylglycol, are about 389 joules per kilogram per kelvin near room temperature. Pressure-dependent neutron scattering measurements reveal that CBCEs in plastic crystals can be attributed to the combination of extensive molecular orientational disorder, giant compressibility and highly anharmonic lattice dynamics of these materials. Our study establishes the microscopic mechanism of CBCEs in plastic crystals and paves the way to next-generation solid-state refrigeration technologies.

Perfusion abnormality on three-dimensional arterial spin labeling with a 3T MR system in pediatric and adolescent patients with migraine.

PURPOSE: Few studies have assessed the prevalence of perfusion abnormality with migraine. This study aimed to determine the prevalence and topography of perfusion abnormality on three-dimensional (3D) arterial spin labeling (ASL) and assess the correlation between perfusion abnormality and clinical data in pediatric and adolescent patients with migraine. METHODS: Forty-nine consecutive pediatric and adolescent patients with migraine were enrolled, and they underwent 3 T MRI, including 3D ASL. Perfusion abnormality on 3D ASL was qualitatively evaluated using a five-point grading system and was compared with non-ASL MR findings. In patients with perfusion abnormality, relative cerebral perfusion signal intensity (rCPS) was measured. Moreover, we compared clinical data and 3D ASL findings between patients with and those without perfusion abnormality. RESULTS: Of the 49 patients, 11 (22%) exhibited perfusion abnormality, and the occipital lobe was the most frequently involved (73%). One patient showed mild hyperperfusion (rCPS =2.474), and 10 showed hypoperfusion (mean rCPS = 0.405 ±â€¯0.134). There was no abnormality on non-ASL MRI, except in one case. We found statistically significant differences in the presence of aura (P < .001), motor disabilities (P = .019), confusion (P = .004), hospitalization (P = .004), between patients with and those without perfusion abnormality. CONCLUSION: In pediatric and adolescent patients with migraine, 3D ASL shows a high prevalence of perfusion abnormality, especially in the occipital lobe. Patients with perfusion abnormality tend to show the specific clinical symptoms at disease onset and need hospitalization.

Emergency radiology after a massive earthquake: clinical perspective.

Earthquakes are unpredictable and inevitable disasters, causing various earthquake-related disorders. Medical imaging, including digital radiography, computed tomography, and magnetic resonance imaging, plays a key role in the evaluation of earthquake-related disorders. We here demonstrate the concept of diagnostic imaging after a massive earthquake and review the common imaging features of various disorders in casualties and evacuees. This summary of imaging features can facilitate the diagnosis of various earthquake-related disorders and promote judicious therapy planning.

Enclathration of Ethane, Propane, and Propylene into Urea Clathrates and Roles of Methanol on Urea Clathrate Formation.

As a guest molecule of urea clathrate, a long-chain normal alkane and its derivative with low substituents in methanol solutions have been reported. To investigate the role of methanol in the urea clathrate formation, in the present study, we used propane (C3H8), propylene (C3H6), ethane (C2H6), and methane (CH4) as guest molecules. Raman spectra and powder X-ray diffraction profiles revealed that, regardless of the existence of methanol, the C3H8, C3H6, and C2H6 molecules are enclathrated into urea clathrates with a hexagonal structure, whereas there is no urea clathrate formation enclathrating CH4. The pressurization of the urea clathrates including C2H6 and C3H8 reveals that no pressure-induced structural phase transition occurs at pressures up to 200 MPa. In spite of the guest molecule much shorter than the lattice constant of the c-axis of the hexagonal channel structure, the urea clathrates have a fairly rigid structure against the compression. Methanol as an auxiliary solution is not always necessary for the urea clathrate formation. Methanol plays a role in decreasing the activation energy of the urea clathrate formation, although it makes urea clathrate thermodynamically unstable due to the high solubility of urea in methanol.

A case of a urethral diverticular adenocarcinoma after the fenestration of the anterior vaginal wall for pelvic floor abscess.

A 61-year-old woman presented to the gynecology department with complaints of atypical genital bleeding. Magnetic resonance imaging revealed a localized urethral tumor extended to vagina. Histological test of the biopsy tissue of the mass suggested the adenocarcinoma. The patient was performed the fenestration of the anterior vaginal wall 15 years ago. Under the diagnosis of urethral diverticular adenocarcinoma, we performed standard open total cystectomy with lymph node excision and ileal conduit. We could not establish a diagnosis of urethral diverticulum from the histological test; however, we clinically diagnosed as urethral diverticular adenocarcinoma. Because carcinoma arising from urethral diverticula is reported, a close long-term follow-up for the recurrence or generation of malignant tumors by genitourinary examinations or images is necessary, for the patient with urethral diverticula.

Circulating Cytokine Levels in Patients with Prostate Cancer: Effects of Neoadjuvant Hormonal Therapy and External-beam Radiotherapy.

AIM: The aim of the study was to better characterize the temporal induction of inflammatory cytokines in the serum of patients with prostate cancer (PCa) treated with radiotherapy and to ascertain the influence of hormonal therapy upon those expressions. PATIENTS AND METHODS: Between May 2007 and December 2009, 30 patients with localized PCa were treated with 3-dimensional conformal external-beam radiotherapy. Fifteen patients had received neoadjuvant hormonal therapy using a leuteinizing hormone-releasing hormone (LH-RH) analog for six months prior to radiotherapy. The cytokine levels were collectively measured using a multiplex assay system. RESULTS: Seventeen cytokines were at detectable levels throughout the blood sampling times before and during radiotherapy. Hormonal therapy for six months significantly decreased the serum levels of fibroblast growth factor-2 (FGF2) and vascular endothelial growth factor (VEGF). The levels of epidermal growth factor (EGF), granulocyte-colony stimulating factor (G-CSF), and interferon-gamma (IFNγ) significantly increased during radiotherapy. Most cytokine levels, except for eotaxin, G-CSF, growth-related oncogene (GRO), transforming growth factor-beta (TGFß)-1 and TGFß2, significantly increased during radiotherapy compared to the levels observed before radiotherapy. CONCLUSION: The present study revealed the influence of hormonal, and of radiation therapy on the proinflammatory cytokine levels in the sera of patients with PCa. In addition, neoadjuvant hormonal therapy amplified the radiation-induced alteration of serum cytokines. Further studies to characterize the mechanism underlying a radiation- or hormone-induced inflammatory state are, therefore, necessary.

Blue-colored tert-butylamine clathrate hydrate.

Clathrate hydrates preserve active species more stably than the other icy materials and investigation of the behavior of the active species elucidates the physicochemical properties of clathrate hydrates like guest-guest interaction. Color of the tert-butylamine clathrate hydrate changes to blue after gamma irradiation and is bleachable with visible light. The electron spin resonance (ESR) spectrum at 120 K mainly consists of a triplet signal of the C-centered radical NH2C(CH3)2CH2• together with a single signal at g = 2.0008. The latter signal disappears after light exposure. These results indicate that both the blue color and the single ESR signal are derived from trapped electrons in the hydrate. They thermally decay around 140-160 K by the first-order reaction, and the activation energy is 27 kJ/mol. Since tert-butylamine molecules can capture protons due to the high proton affinity, electrons may remain in the hydrate without reacting with protons, making the hydrate blue after gamma irradiation. The long-lived trapped electrons in the tert-butylamine hydrate have an advantage to investigate those in icy materials because tert-butylamine hydrate is nonionic and has a tetra-coordinated host water network like crystalline ice without any substitution for water molecules.

Synergistic formation of carboxyl and methyl radicals in CO2 + methane mixed gas hydrates.

The formation mechanisms of γ-ray-induced carboxyl (HOCO) and methyl radicals in CO2 + methane mixed gas hydrates, which are inclusion compounds of H2O, CO2, and methane, were investigated. The HOCO and methyl radicals were observed in CO2 + methane mixed gas hydrates by electron spin resonance (ESR) at 120 K after irradiation at 77 K. The amounts of the HOCO and methyl radicals induced in the mixed hydrates are much higher than those in pure CO2 and methane hydrates. Both radicals are synergistically formed in the mixed hydrates by efficient reactions between the guest molecules (CO2 and methane) and the active species (electron, proton, and hydroxyl radical) induced from H2O.

Nucleophilic reactions of bromocyclopentane in the structure-H methane + bromocyclopentane mixed hydrate system at high pressures.

Thermodynamic stability boundary in the structure-H methane + bromocyclopentane mixed hydrate system was measured at pressures from 20 to 100 MPa. The thermodynamic stability boundary of the methane + bromocyclopentane mixed hydrate exhibits anomalous behavior under conditions at high pressures and high temperatures. This phenomenon is due to the elimination and substitution reactions of bromocyclopentane to cyclopentene and cyclopentanol, respectively. The nucleophilic reactions of bromocyclopentane are mainly advanced in the liquid bromocyclopentane-rich phases, while it is restrained when bromocyclopentane is enclathrated in hydrate cage.

Reactions of HOCO radicals through hydrogen-atom hopping utilizing clathrate hydrates as an observational matrix.

The carboxyl (HOCO) radical, which is an important species in atmospheric chemistry and combustion, is an intermediate in the reaction: CO + OH → CO2 + H and serves as a hydrogen donor to the reaction partners. The cis-HOCO radical, one of the ground-state HOCO radicals, is supposed to be decomposed into CO2 and the hydrogen atom by a tunneling effect. In order to prove the hypothesis, we performed electron spin resonance (ESR) measurements to investigate the decay mechanisms of the ground-state HOCO and DOCO radicals in gamma-ray-irradiated CO2 hydrates, which may hold the radicals stably. The ground-state HOCO and DOCO radicals decayed according to a second-order decay model and transformed into formic acid and CO2. The ratio of the decay rate constants of HOCO and DOCO radicals shows a good agreement with that in the kinetic isotope effect for the hydrogen and deuterium abstraction reactions. These results indicate that they react with another HOCO radical in the adjacent hydrate cage without the tunneling effect. This implies that the ground-state HOCO radicals are not decomposed by the tunneling effect but are decayed through reactions with some atoms, molecules, and/or radicals even in the gas phase. In addition, the hydrogen-atom hopping through the temporary hydrogen bonds between the HOCO radical and CO2 results in a seeming diffusion of the HOCO radicals in the CO2 hydrate; this would be an important concept for the studies of the radical diffusions and the supply of hydrogen atoms in gas, liquid, and solid phases.

Postcatheterization radial arteriovenous fistula: balloon-assisted direct percutaneous embolization with N-butyl cyanoacrylate and 50 % glucose solution in two sessions.

We report an iatrogenic radial arteriovenous fistula (AVF) in a 74-year-old woman presenting with right radial bruit and pain 8 months after sheath removal for cardiac catheterization. She refused surgical ligation and underwent balloon-assisted direct percutaneous embolization of the draining vein with N-butyl cyanoacrylate (NBCA). Another draining vein that developed immediately after the procedure was conservatively treated with 1 month of continuous band compression. However, its diameter gradually increased and, as the patient desired complete remission, an additional procedure was conducted 2 months after initial treatment. A second balloon-assisted direct percutaneous embolization was performed using a 50 % glucose solution, which resulted in complete resolution. Although surgical repair is considered to be the standard treatment, in patients where surgery is not indicated, endovascular intervention-although complicated-may be an alternative treatment modality.

Structure-H methane + 1,1,2,2,3,3,4-heptafluorocyclopentane mixed hydrate at pressures up to 373 MPa.

Thermodynamic stability boundary of structure-H hydrates with large guest species and methane (CH4) at extremely high pressures has been almost unclear. In the present study, the four-phase equilibrium relations in the structure-H CH4 + 1,1,2,2,3,3,4-heptafluorocyclopentane (1,1,2,2,3,3,4-HFCP) mixed hydrate system were investigated in a temperature range of (281.05 to 330.12) K and a pressure range up to 373 MPa. The difference between equilibrium pressures in the structure-H CH4 + 1,1,2,2,3,3,4-HFCP mixed hydrate system and the structure-I simple CH4 hydrate system gets larger with increase in temperature. The structure-H CH4 + 1,1,2,2,3,3,4-HFCP mixed hydrate survives even at 330 K and 373 MPa without any structural phase transition. The maximum temperature where the structure-H CH4 + 1,1,2,2,3,3,4-HFCP mixed hydrate is thermodynamically stable is likely to be beyond that of the structure-H simple CH4 hydrate.

Percutaneous removal of a fully expanded SMART stent from the pulmonary artery using various adjunctive techniques.

A 36-year-old man with an implanted arteriovenous shunt for hemodialysis was referred for shunt malfunction. Venography of the right upper extremity showed occlusion of the subclavian vein, and a SMART stent was deployed. The fully expanded stent immediately migrated centrally into the left pulmonary artery. As initial efforts to pass a snare over the stent failed, we intentionally passed a microguidewire through stent interstices, snared the end of the microguidewire to create a loop, and pulled the stent/microguidewire/snare combination back into the right ventricle where it separated from the loop because of stent mesh destruction. As the stent remained in the right ventricle, we advanced a 0.035-in. guidewire into the stent lumen, passed an angioplasty balloon over the guidewire, inflated the balloon in the stent, and performed pull-back into the right distal external iliac artery. The stent was then surgically removed via a right inguinal incision without eliciting any complications. Although retrieval of the stent malpositioned in the pulmonary artery was difficult, we retrieved it safely by applying various adjunctive techniques.

Intermolecular hydrogen transfer between guest species in small and large cages of methane + propane mixed gas hydrates.

To investigate the molecular interaction between guest species inside of the small and large cages of methane + propane mixed gas hydrates, thermal stabilities of the methyl radical (possibly induced in small cages) and the normal propyl and isopropyl radicals (induced in large cages) were investigated by means of electron spin resonance measurements. The increase of the total amount of the normal propyl and isopropyl radicals reveals that the methyl radical in the small cage withdraws one hydrogen atom from the propane molecule enclathrated in the adjacent large cage of the structure-II hydrate. A guest species in a hydrate cage has the ability to interact closely with the other one in the adjacent cages. The clathrate hydrate may be utilized as a possible nanoscale reaction field.