Effects of volatile anesthetics on circadian rhythm in mice: a comparative study of sevoflurane, desflurane, and isoflurane.

PURPOSE: Volatile anesthetics affect the circadian rhythm of mammals, although the effects of different types of anesthetics are unclear. Here, we anesthetized mice using several volatile anesthetics at two different times during the day. Our objective was to compare the effects of these anesthetics on circadian rhythm. METHODS: Male adult C57BL/6 J mice were divided into eight groups (n = 8 each) based on the anesthetic (sevoflurane, desflurane, isoflurane, or no anesthesia) and anesthesia time (Zeitgeber time [ZT] 6-12 or ZT18-24). Mice were anesthetized for 6 h using a 0.5 minimum alveolar concentration (MAC) dose under constant dark conditions. The difference between the start of the active phase before and after anesthesia was measured as a phase shift. Clock genes were measured by polymerase chain reaction in suprachiasmatic nucleus (SCN) samples removed from mouse brain after anesthesia (n = 8-9 each). RESULTS: Phase shift after anesthesia at ZT6-12 using sevoflurane (- 0.49 h) was smaller compared with desflurane (- 1.1 h) and isoflurane (- 1.4 h) (p < 0.05). Clock mRNA (ZT6-12, p < 0.05) and Per2 mRNA (ZT18-24, p < 0.05) expression were different between the groups after anesthesia. CONCLUSION: 0.5 MAC sevoflurane anesthesia administered during the late inactive to early active phase has less impact on the phase shift of circadian rhythm than desflurane and isoflurane. This may be due to differences in the effects of volatile anesthetics on the expression of clock genes in the SCN, the master clock of the circadian rhythm.

Association between remimazolam and postoperative delirium in older adults undergoing elective cardiovascular surgery: a prospective cohort study.

PURPOSE: Postoperative delirium is one of the most common complications after cardiovascular surgery in older adults. Benzodiazepines are a reported risk factor for delirium; however, there are no studies investigating remimazolam, a novel anesthetic agent. Therefore, we prospectively investigated the effect of remimazolam on postoperative delirium. METHODS: We included elective cardiovascular surgery patients aged ≥ 65 years at Hamamatsu University Hospital between August 2020 and February 2022. Patients who received general anesthesia with remimazolam were compared with those who received other anesthetics (control group). The primary outcome was delirium within 5 days after surgery. Secondary outcomes were delirium during intensive care unit stay and hospitalization, total duration of delirium, subsyndromal delirium, and differences in the Mini-Mental State Examination scores from preoperative to postoperative days 2 and 5. To adjust for differences in the groups' baseline covariates, we used stabilized inverse probability weighting as the primary analysis and propensity score matching as the sensitivity analysis. RESULTS: We enrolled 200 patients; 78 in the remimazolam group and 122 in the control group. After stabilized inverse probability weighting, 30.3% of the remimazolam group patients and 26.6% of the control group patients developed delirium within 5 days (risk difference, 3.8%; 95% confidence interval -11.5% to 19.1%; p = 0.63). The secondary outcomes did not differ significantly between the groups, and the sensitivity analysis results were similar to those for the primary analysis. CONCLUSION: Remimazolam was not significantly associated with postoperative delirium when compared with other anesthetic agents.

Obstetric admission to intensive care units in Japan: a cohort study using the Japanese Intensive care PAtient Database.

PURPOSE: This study aimed to describe the epidemiology and annual trends of obstetric patients using a multicenter intensive care database. METHODS: This multicenter, retrospective cohort study used the Japanese Intensive care PAtient Database (JIPAD). We included obstetric patients registered in the JIPAD between 2015 and 2020. We investigated the proportion of obstetric patients among all patients in the intensive care unit (ICU). We also described the characteristics, procedures, and outcomes of obstetric patients. In addition, the annual trends were examined by nonparametric tests for trends. RESULTS: Of the 184,705 patients enrolled in the JIPAD, 750 (0.41%) were obstetric patients from 61 facilities. The median age was 34 years, the number of post-emergency surgeries was 450 (60.0%), and the median APACHE III score was 36. Mechanical ventilation was the most common procedure performed in 247 (32.9%) patients. There were five (0.7%) in-hospital deaths. The proportion of obstetric patients in the ICU did not change between 2015 and 2020 (P for trend = 0.32). However, there was a trend for a significant decrease in the severity of illness and length of hospital stay on an annual basis between 2015 and 2020. Most patients were admitted to the ICU because of a pregnancy-related disorder postoperatively. CONCLUSION: The proportion of obstetric patients was 0.41% of all ICU admissions. The proportion of obstetric patients admitted to the ICU did not change from 2015 to 2020, but the patients' severity of illness and length of hospital stay significantly decreased over time.

Effects of fentanyl administration in mechanically ventilated patients in the intensive care unit: a systematic review and meta-analysis.

BACKGROUND: Fentanyl is selected to manage pain in critical care patients on mechanical ventilation in the intensive care unit (ICU). However, the usefulness of fentanyl compared with other opioids is unknown. This study examined the evidence for using fentanyl to improve the clinical outcomes of ICU patients, using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. METHODS: We searched the MEDLINE, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi databases in June 2021. Two independent assessors reviewed studies to identify randomized, controlled trials (RCTs) that compared the intravenous administration of fentanyl and other opioids in mechanically ventilated patients in the ICU. The study quality was assessed using the GRADE system and Cochrane methodology. The primary outcome was mortality. The secondary outcomes were the duration of mechanical ventilation, duration of the ICU stay, incidence of severe adverse events, and incidence of delirium. We integrated outcome data using a random-effects model and showed absolute values and certainty of evidence in the GRADE evidence profile. RESULTS: Seven RCTs met the study inclusion criteria with 534 patients (251 were treated with fentanyl and 283 with other opioids, including 242 with remifentanil and 41 with morphine). Among 191 participants from 2 RCTs, fentanyl was not associated with mortality (risk ratio [RR], 0.79; 95% confidence interval [CI], 0.24 to 2.60; low-quality evidence). Regarding the secondary outcomes, fentanyl did not shorten the duration of mechanical ventilation (mean difference, 0.49 h; 95% CI, - 0.90 to 1.88; moderate-quality evidence) or the duration of the ICU stay (mean difference, 7.04 h; 95% CI, - 3.27 to 17.35; moderate-quality evidence) compared with other opioids. Fentanyl did not increase the incidence of severe adverse events (RR, 0.98; 95% CI, 0.50 to 1.90; low-quality evidence) or delirium (RR, 1.27; 95% CI, 0.79 to 2.04; low-quality evidence). CONCLUSIONS: Although fentanyl is a frequently administered opioid in the ICU, patients' outcomes are not different between fentanyl use and use of other opioids. However, the GRADE evaluation provides little certainty to support the results of this systematic review. Therefore, further large RCTs are required to confirm our conclusions. TRIAL REGISTRATION: PROSPERO, CRD42019130648 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=130648 ).

In Situ Activation of a Manganese Perovskite Oxygen Reduction Catalyst in Concentrated Alkaline Media.

The reaction pathway of the oxygen reduction reaction (ORR) is strongly affected by the electrolytic environment. Meanwhile, the ORR mechanism on transition-metal oxide catalysts has not been studied intensely in very concentrated alkaline solutions that are used in practical metal-air batteries. Herein, we report the in situ activation of ORR catalysis on manganese perovskite in a concentrated alkaline solution, mediated by the spontaneous formation of oxygen vacancy sites. Electrochemical analyses of the (100) epitaxial film electrodes reveal that the exchange current and electron number of the ORR on La0.7Sr0.3Mn0.9Ni0.1O3 significantly increase with the duration of the ORR when the KOH concentration is greater than 4 M. However, these values remain unchanged with time at less than 1 M KOH concentration. Operando synchrotron X-ray spectroscopy of the (100) epitaxial film confirmed that La0.7Sr0.3Mn0.9Ni0.1O3 involves the oxygen vacancy sites with the reduction of Mn atoms in concentrated KOH solution via the hydroxylation decomposition of perhydroxyl intermediates. Hence, the O2 adsorption switched from an end-on to a bidentate mode because the cooperative active sites of the oxygen vacancy and neighboring Mn allow bidentate adsorption of the dissolved O2. Due to the simultaneous interaction with the oxygen vacancy and Mn sites, the O-O bonds are activated and the potential barrier for the electron transfer to adsorbed O2 is lowered, resulting in a shift in the reaction mechanism from that involving an indirect "2 + 2" transfer pathway to a direct 4-electron pathway.

Phrenic Nerve Block at the Azygos Vein Level Versus Sham Block for Ipsilateral Shoulder Pain After Video-Assisted Thoracoscopic Surgery: A Randomized Controlled Trial.

BACKGROUND: Ipsilateral shoulder pain (ISP) is a common problem after pulmonary surgery. We hypothesized that phrenic nerve block (PNB) at the azygos vein level, near the location of the surgical operation, would be effective for reducing ISP. Our primary aim was to assess the effect of PNB on postoperative ISP, following video-assisted thoracic surgery (VATS). METHODS: This prospective, randomized, patient-blinded, single-institution trial was registered at the University Hospital Medical Information Network (UMIN000030464). Enrolled patients had been scheduled for VATS under general anesthesia with epidural analgesia. Patients were randomly allocated to receive infiltration of the ipsilateral phrenic nerve at the azygos vein level with either 10 mL of 0.375% ropivacaine (PNB group) or 0.9% saline (control group) before chest closure. Postoperative ISP was assessed using a numerical rating scale (NRS, 0-10) at rest at 2, 4, 8, 16, and 24 hours. The incidence of ISP was defined as the proportion of patients who reported an NRS score of ≥1 at least once within 24 hours after surgery. In the primary analysis, the proportion of patients with ISP was compared between PNB and control groups using the χ2 test. NRS values of ISP and postoperative incision pain within 24 hours were investigated, as was the frequency of postoperative analgesic use. Incision pain was assessed using an NRS at the time of ISP assessment. Finally, the incidence of postoperative nausea and vomiting and shoulder movement disorders were also evaluated. RESULTS: Eighty-five patients were included, and their data were analyzed. These patients were randomly assigned to either PNB group (n = 42) or control group (n = 43). There were no clinically relevant differences in demographic and surgical profiles between the groups. There was no significant difference in the incidence of ISP (the control group 20/43 [46.5%] versus the PNB group 14/42 [33.3%]; P = .215). The severity of ISP was lower in the PNB group than in the control group (linear mixed-effects model, the main effect of treatment [groups]: P < .001). There were no significant differences between groups in terms of postoperative incision pain. The frequency of postoperative analgesic use was significantly higher in the control group (Wilcoxon rank sum test, P < .001). Postoperative nausea and vomiting did not significantly differ between the 2 groups. There were no changes in the range of shoulder joint movement. CONCLUSIONS: Azygos vein level PNB did not significantly affect the incidence of ISP after VATS.

The Impact of Nocturia on Mortality: A Systematic Review and Meta-Analysis.

PURPOSE: Nocturia (waking from sleep at night to void) is a common cause of sleep disruption associated with increased comorbidity and impaired quality of life. However, its impact on mortality remains unclear. We performed a systematic review and meta-analysis to evaluate the association of nocturia with mortality as a prognostic factor and a causal risk factor. MATERIALS AND METHODS: We searched PubMed®, Scopus®, CINAHL® (Cumulative Index of Nursing and Allied Health Literature) and major conference abstracts up to December 31, 2018. Random effects meta-analyses were done to address the adjusted RR of mortality in people with nocturia. Meta-regression was performed to explore potential determinants of heterogeneity, including the risk of bias. We applied the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) framework to rate the quality of evidence for nocturia as a prognostic risk factor for mortality and separately as a cause of mortality. RESULTS: Of the 5,230 identified reports 11 observational studies proved eligible for inclusion. To assess nocturia 10 studies used symptom questionnaires and 1 used frequency-volume charts. Nocturia was defined as 2 or more episodes per night in 6 studies (55%) and as 3 or more episodes per night in 5 (45%). Pooled estimates demonstrated a RR of 1.27 (95% CI 1.16-1.40, I2=48%) with an absolute 1.6% and 4.0% 5-year mortality difference in individuals 60 and 75 years old, respectively. The pooled estimates of relative risk did not differ significantly across varying age, gender, followup, nocturia case definition, risk of bias or study region. We rated the quality of evidence for nocturia as a prognostic factor as moderate and as a cause of mortality as very low. CONCLUSIONS: Nocturia is probably associated with an approximately 1.3-fold increased risk of death.

The Impact of Nocturia on Falls and Fractures: A Systematic Review and Meta-Analysis.

PURPOSE: Although nocturia is associated with various comorbidities, its impact on falls and fractures remains unclear. We performed a systematic review and meta-analysis to evaluate the association between nocturia and falls and fractures as a prognostic and as a causal risk factor. MATERIALS AND METHODS: We searched PubMed®, Scopus®, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and abstracts of major urological meetings up to December 31, 2018. We conducted random effects meta-analyses of adjusted relative risks of falls and fractures. We applied the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach to rate the quality of evidence for nocturia as a prognostic and causal factor of falls and fractures. RESULTS: Among 5,230 potential reports 9 observational longitudinal studies provided data on the association between nocturia and falls or fractures (1 for both, 4 for falls, 4 for fractures). Pooled estimates demonstrated a risk ratio of 1.20 (95% CI 1.05-1.37, I2=51.7%, annual risk difference 7.5% among the elderly) for association between nocturia and falls and 1.32 (95% CI 0.99-1.76, I2=57.5%, annual risk difference 1.2%) for association between nocturia and fractures. Subgroup analyses showed no significant effect modification by age, gender, followup time, nocturia case definition or risk of bias. We rated the quality of evidence for nocturia as a prognostic factor as moderate for falls and low for fractures, and as very low as a cause of falls/fractures. CONCLUSIONS: Nocturia is probably associated with an approximately 1.2-fold increased risk of falls and possibly an approximately 1.3-fold increased risk of fractures.

Low and high body mass index values are associated with female nocturia.

AIMS: We evaluated the relationship between body mass index (BMI), including low BMI, and nocturia in Japanese women. METHODS: We collected data on 18 952 women who participated in a multiphasic health screening in Fukui, Japan, in 2006. The participants were asked to report any current or previous disease. Self-reported current body weight and height were used to calculate the BMI. We analyzed the relationship between nocturia, as assessed by a questionnaire, and other variables including age, BMI, and comorbidities. RESULTS: The participants' mean age was 60.6 years. Overall, the prevalence of nocturia (two or more voids/night) was 4.3% and increased in an age-dependent manner. BMI did not affect nocturia in the young participants. The prevalence of nocturia was higher in the high-BMI women (>25.0 kg/m 2 ) in their fifth and sixth decades, but the prevalence was higher in the low-BMI (<18.5 kg/m 2 ) in the women more than 80-years old. A multivariate analysis revealed a significant association between nocturia and the following: age, BMI, sleep disturbance, arteriosclerosis, cerebrovascular disease, chronic pulmonary disease, diabetes mellitus, and hypertension. Not only high BMI (which is already reported as a risk of nocturia) but also low BMI was a factor related to nocturia. CONCLUSION: Our findings indicate that in addition to obesity, low BMI is a factor of nocturia in women.

α1 -Blocker inhibits non-voiding contractions and decreases the level of intravesical prostaglandin E2 in rats with partial bladder outlet obstruction.

OBJECTIVES: To elucidate the mechanism of action of the α1 -blocker, naftopidil, in partial bladder outlet obstruction animals, by studying non-voiding contractions, and the levels of mediators were measured with resiniferatoxin treatment. METHODS: A total of 35 female Wistar rats were randomly divided into a sham or bladder outlet obstruction group, and rats in each group were given vehicle or resiniferatoxin. Incomplete urethral ligation was applied to the bladder outlet obstruction group. After cystometry, the intravesical level of prostaglandin E2 and adenosine 5'-triphosphate was measured in the instilled perfusate collected. Naftopidil was given at the time of cystometry. RESULTS: In bladder outlet obstruction rats, non-voiding contractions, bladder capacity, and the intravesical levels of prostaglandin E2 and adenosine 5'-triphosphate were markedly increased compared with sham rats. Naftopidil decreased non-voiding contractions, enlarged the bladder capacity, and decreased the intravesical levels of prostaglandin E2 and adenosine 5'-triphosphate. Resiniferatoxin enhanced non-voiding contractions. The effects of naftopidil on non-voiding contractions and the intravesical level of prostaglandin E2 , but not adenosine 5'-triphosphate, were tolerant to resiniferatoxin. CONCLUSIONS: In bladder outlet obstruction rats, one cause of generation of non-voiding contractions might be bladder wall distension, but not transient receptor potential cation channel V1. The increase in intravesical prostaglandin E2 might also be associated with the generation of non-voiding contractions. Naftopidil inhibits the increase in non-voiding contractions and decreases the intravesical level of prostaglandin E2 , which are independent of transient receptor potential cation channel V1.

Low-Temperature Oxygen Storage of CrIV-CrV Mixed-Valence YCr1-xPxO4-δ Driven by Local Condensation around Oxygen-Deficient Orthochromite.

The oxygen storage capability and related defect structure of tetrahedral orthochromite(V) compound YCr1-xPxO4 (x = 0, 0.3, 0.5, and 0.7) were investigated by employing thermal gravimetry and in situ X-ray spectroscopy for reversible oxygen store/release driven by heating-cooling cycles in the temperature range from 50 to 600 °C. YCr1-xPxO4 started releasing oxygen as heated from 50 °C under ambient atmosphere, with reduction of CrV to CrIV, while the reduced YCr1-xPxO4-δ phase was significantly reoxidized via absorbing oxygen by cooling to 50 °C under ambient atmosphere, recovering the original stoichiometric phase. Operando X-ray adsorption spectroscopy and first-principles calculations demonstrate that nonstoichiometric YCr1-xPxO4-δ phases were stabilized by forming linking polyhedral CrIV2O76- via corner sharing between oxygen-deficient CrIVO32- and adjacent CrIVO44-. YCr1-xPxO4 was found to have an extremely low reduction enthalpy of about 20 kJ mol-1 probably due to the relatively high reduction potential of high-valence-state Cr(V)/Cr(IV) redox pairs, thereby resulting in reversible oxygen storage in such a low-temperature region.

Perioperative Amino Acid Infusion for Preventing Hypothermia and Improving Clinical Outcomes During Surgery Under General Anesthesia: A Systematic Review and Meta-analysis.

Amino acid (AA) infusion is sometimes selected to avoid hypothermia during general anesthesia. However, the widespread clinical use of AA infusion therapy has not been established. This study aimed to clarify the evidence that AA infusion can increase patient body temperature and improve clinical outcomes using the Grading of Recommendations Assessment, Development, and Evaluation system. We searched MEDLINE (PubMed), Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi (Japana Centra Revuo Medicina) in November 2015. Studies were reviewed by 2 independent assessors to identify randomized controlled trials (RCTs) involving AA infusion compared with placebos during surgery under general or combined general/epidural anesthesia. Study quality was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system and the Cochrane methodology. The primary outcome was difference in body temperature before and after perioperative AA infusion. Shivering frequency, blood loss volume, postoperative intubation time, and hospitalization period were also assessed as clinical outcomes. We analyzed the outcome data using a random effect model. From 298 screened titles, 14 RCTs met our inclusion criteria, including 626 patients (327 in AA and 299 in placebo groups). In 626 participants from 14 RCTs, AA infusion increased body temperature by a mean difference (MD) of 0.46°C (95% confidence interval [CI], 0.31-0.62, low-quality evidence). Regarding other outcomes, AA infusion decreased shivering frequency by a risk ratio of 0.34 (95% CI, 0.12-0.94; 7 RCTs, 248 participants, very low-quality evidence), shortened postoperative intubation time by MD of -125 minutes (95% CI, -210 to -38.8; 2 RCTs, 158 participants, moderate-quality evidence), and shortened the hospitalization period by MD of -1.81 days (95% CI, -2.07 to -1.55; 3 RCTs, 230 participants, low-quality evidence) compared with placebo. There was no significant difference in the volume of blood loss between the 2 groups (standardized MD, -0.20, 95% CI, -0.44 to 0.04; low-quality evidence). There was no publication bias. AA infusion in the perioperative period increased patient body temperature and improved clinical outcomes compared with placebo. However, the evidence to support the use of AA infusion is limited, and further large-scale RCTs are required.

[Adult Male Ureterocele Detected by Urinary Frequency].

A 27-year-old Japanese man visited our urological department due to urinary frequency, and we detected a ureterocele by cystoscopy. The treatment consisted of an endoscopic-laser incision of the ureterocele. After the operation, the patient's symptoms subsided, and the vesicoureteral reflux and urinary infection disappeared. With the advances in image diagnostic technology, a ureterocele is easily diagnosed during childhood. In the present case, the ureterocele may have increased in volume over a period of decades, causing the urinary frequency. An endoscopic incision is the standard treatment for ureterocele, but there are concerns about vesicoureteric reflux after the endoscopic-laser incision, the patient is still doing well. The present case indicates that endoscopic-laser incision is an effective treatment for a ureterocele, at least in adult patients.

Corrosion protection of iron using porous anodic oxide/conducting polymer composite coatings.

Conducting polymers (CPs), including polypyrrole, have attracted attention for their potential in the protection of metals against corrosion; however, CP coatings have the limitation of poor adhesion to metal substrates. In this study, a composite coating, comprising a self-organized porous anodic oxide layer and a polypyrrole layer, has been developed on iron. Because of electropolymerization in the pores of the anodic oxide layer, the composite coating showed improved adhesion to the substrate along with prolonged corrosion protection in a NaCl aqueous corrosive environment. The anodic oxide layers are formed in a fluoride-containing organic electrolyte and contain a large amount of fluoride species. The removal of these fluoride species from the oxide layer and the metal/oxide interface region is crucial for improving the corrosion protection.

Radial artery cannulation decreases the distal arterial blood flow measured by power Doppler ultrasound.

Radial arterial cannulation is a popular technique for continuous hemodynamic monitoring in an area of anesthesia and intensive care. Although the risk for invasive monitoring is considerable, there is scarce information about the change in blood flow of cannulated vessel after the catheterization. In the current investigation, we evaluated the change in the cannulated arterial blood flow. Six volunteers (study 1) and eight post-surgical patients (study 2) were enrolled into the studies. In the study 1, the both side of diameter of radial artery (RA), ulnar artery (UA) and dorsal branch of radial artery (DBRA) of participants were measured using power Doppler ultrasound (PDU) with or without proximal oppression. In the study 2, the diameter of RA, UA and DBRA of the both intact and cannulated side were compared. Study 1: The diameter of RA was 3.4 (0.52) [mean (SD)] mm and the proximal oppression significantly decreased the diameter to 1.8 (0.59) mm. The diameter of DBRA measured by PDU also decreased 2.0 (0.60)-1.3 (0.59) mm. Study 2: There was no difference between the diameters of right and left RA, however, the UA was larger [3.4 (0.60) vs. 2.8 (0.83) mm] and the DBRA was narrower [1.4 (0.43) vs. 2.0 (0.47) mm] in the cannulated side. The diameters of DBRA were different between the intact and cannulated side in the patients. Although there is no information of relationships between cause of severe complication and decreased flow, significant reduction of blood flow should be concerned.

[A case of metachronal testicular tumor eight years after medical treatment of extragonadal germ cell tumor].

A 22-year-old man was admitted to our hospital complaining of a left cervical mass. Computed tomography (CT) showed multiple enlarged lymph nodes at the left cervical vein and para-aortic areas. Histological examination of a biopsy indicated an embryonal carcinoma. The levels of human ß-chorionic gonadotropin (ß-HCG) and lactic dehydrogenase (LDH) were both elevated. Ultrasonography revealed testicular calcification, but there were no findings on magnetic resonance imaging (MRI). The patient was diagnosed as having an extragonadal germ cell tumor. After four courses of chemotherapy with BEP protocol (bleomycin, etoposide and cisplatin), retroperineal lymph node dissection (RPLND) was performed and there was no involvement of the viable cells in the resected lymph nodes. Eight years after chemotherapy, he noticed an enlargement of his left scrotum without pain. ß-HCG was again elevated. A unilateral high orchiectomy was performed, and histology revealed a seminoma. He was staged as pT1N0M0S0. Six months later he remains disease-free.

[Changes in Electrolytic Concentration Resulting from Perioperative Amino Acid Fluid Administration].

BACKGROUND: Amino acid infusion is frequently selected to avoid hypothermia during surgery. However, changes in electrolytic concentration resulting from its use are unclear. The aim of this study was to identify the effect of amino acid on body temperature and changes in electrolytic concentrations. METHODS: Thirty women undergoing breast cancer surgery under general anesthesia were divided into the following three groups: no amino acid administration, low-dose administration (2 ml x kg(-1) x hr(-1)), and high-dose administration (4 ml x kg(-1) x hr(-1)). Esophageal temperature was recorded every ten minutes and arterial blood samples were obtained before and after surgery. Body temperatures at each time point and arterial blood gas data, including blood gases, electrodes, serum glucose, and hematocrit were compared between the three groups. RESULTS: Body temperature started to increase significantly 40 minutes after starting general anesthesia in the high-dose group, 90 minutes after starting general anesthesia in the low-dose group compared with the no amino acid group. Body temperature was maintained until surgery was completed. The concentration of sodium ion decreased significantly (2.4 mmol x l(-1)) in the high-dose group compared with the other two groups. The concentration of other electrolytes, including potassium, chloride, and calcium, did not change significantly. CONCLUSIONS: Perioperative amino acid administration was effective in maintaining a stable body temperature during surgery under general anesthesia. However, sodium ion concentration might decrease after amino acid administration of 4 ml x kg(-1) x hr(-1) or greater.

Unveiling the Origin of Fast Hydride Ion Diffusion at Grain Boundaries in Nanocrystalline TiN Membranes.

Nanocrystalline titanium nitride (TiN) has been determined to be a promising alternative to noble metal palladium (Pd) for fabricating base membranes for the energy-efficient production of pure hydrogen. However, the mechanism of transport of hydrogen through a TiN membrane remains unclear. In this study, we established an atomistic model of the transport of grain boundary hydride ions through such a membrane. High-resolution transmission electron microscopy and X-ray reflectivity confirmed that a nanocrystalline TiN1.0 membrane with a (100) preferred growth orientation retained about 4 Å-wide interfacial spaces along its grain boundaries. First-principles calculations based on the density functional theory showed that these grain boundaries allowed the diffusion of interfacial hydride ion defects with very small activation barriers (<12 kJ mol-1). This was substantiated by the experiment. In addition, the narrow boundary produced a sieving effect, resulting in a selective H permeation. Both the experimental and theoretical results confirmed that the granular microstructures with the 4 Å-wide interlayer enabled the transition metal nitride to exhibit pronounced hydrogen permeability.