Study of Glass Formation and Crystallization Kinetics in a 2D Metal Halide Perovskite Using Ultrafast Calorimetry.

While crystalline 2D metal halide perovskites (MHPs) represent a well-celebrated semiconductor class, supporting applications in the fields of photovoltaics, emitters, and sensors, the recent discovery of glass formation in an MHP opens many new opportunities associated with reversible glass-crystalline switching, with each state offering distinct optoelectronic properties. However, the previously reported [S-(-)-1-(1-naphthyl)ethylammonium]2PbBr4 perovskite is a strong glass former with sluggish glass-crystal transformation time scales, pointing to a need for glassy MHPs with a broader range of compositions and crystallization kinetics. Herein we report glass formation for low-melting-temperature 1-MeHa2PbI4 (1-MeHa = 1-methyl-hexylammonium) using ultrafast calorimetry, thereby extending the range of MHP glass formation across a broader range of organic (fused ring to branched aliphatic) and halide (bromide to iodide) compositions. The importance of a slight loss of organic and hydrogen iodide components from the MHP in stabilizing the glassy state is elucidated. Furthermore, the underlying kinetics of glass-crystal transformation, including activation energies, crystal growth rate, Angell plot, and fragility index, is studied using a combination of kinetic, thermodynamic, and rheological modeling techniques. An inferred fast crystal growth rate of 0.21 m/s for 1-MeHa2PbI4 shows promise toward suitability in extended application spaces, for example, in metamaterials, nonvolatile memory, and optical and neuromorphic computing devices.

Spiers Memorial Lecture: Next generation chalcogenide-based absorbers for thin-film solar cells.

Inorganic-based thin-film photovoltaics (TFPV) represents an important component of the growing low-carbon energy market and plays a vital role in the drive toward lower cost and increased penetration of solar energy. Yet, commercialized thin-film absorber technologies suffer from some non-ideal characteristics, such as toxic or non-abundant element use (e.g., CdTe and Cu(In,Ga)(S,Se)2, which bring into question their suitability for terawatt deployment. Numerous promising chalcogenide, halide, pnictide and oxide semiconductors are being pursued to bridge these concerns for TFPV and several promising paths have emerged, both as prospective replacements for the entrenched technologies, and to serve as partner (i.e., higher bandgap) absorbers for tandem junction devices-e.g., to be used with a lower bandgap Si bottom cell. The current perspective will primarily focus on emerging chalcogenide-based technologies and provide both an overview of absorber candidates that have been of recent interest and a deeper dive into an exemplary Cu2BaSnS4-related family. Overall, considering the combined needs of high-performance, low-cost, and operational stability, as well as the experiences gained from existing commercialized thin-film absorber technologies, chalcogenide-based semiconductors represent a promising direction for future PV development and also serve to highlight common themes and needs among the broader TFPV materials family.

Variation in intraocular pressure caused by repetitive positional changes during laparoscopic colorectal surgery: a prospective, randomized, controlled study comparing propofol and desflurane anesthesia.

Laparoscopic surgery is often prolonged and requires positional changes to facilitate surgical access. Previous studies reported intraocular pressure (IOP) changes in one fixed position. This study investigated the effect of desflurane and propofol anesthesia on IOP during repeated positional changes. A total of 46 patients undergoing laparoscopic colorectal surgery were randomized into desflurane or propofol groups. IOP was measured using a handheld tonometer at seven time points: before induction (baseline), after endotracheal intubation, after pneumoperitoneum, after the first Trendelenburg and right tilt position, after reverse Trendelenburg and right tilt position, after the second Trendelenburg and right tilt position and before endotracheal extubation. Trendelenburg positioning raised IOP in both groups. In the desflurane group, IOP at the first Trendelenburg position was 6.27 and 8.48 mmHg higher than baseline IOP in left and right eye, respectively; IOP at the second Trendelenburg position was 7 and 9.44 mmHg higher than baseline in left and right eye, respectively. In the propofol group, IOP at the first Trendelenburg position was 2.04 and 4.04 mmHg higher than baseline in left and right eyes, respectively. It was 3.04 and 4.87 mmHg higher than baseline in left and right eye, respectively, at the second Trendelenburg position. In the desflurane group, 56.52% patients exhibited high IOP (≥ 25 mmHg) compared with 13.04% in the propofol group at the second Trendelenburg position in the right eyes (P = 0.005). There was a positive correlation between IOP and peak inspiratory pressure (P < 0.001). Propofol anesthesia mitigated wide variations in IOP caused by repetitive positional changes during laparoscopic colorectal surgery.

Optimal dose of prophylactic dexmedetomidine for preventing postoperative shivering.

OBJECTIVE: The aim of this study was to investigate the optimum dosage of dexmedetomidine for prevention of postanesthetic shivering. METHODS: One-hundred thirty two ASA physical status I-II patients scheduled for elective laparoscopic total hysterectomy were enrolled in this randomised, placebo-controlled study. Patients were randomly allocated to receive dexmedetomidine in four groups: group S (0.9% normal saline), group D0.5 (dexmedetomidine 0.5 µg/kg), group D0.75 (dexmedetomidine 0.75 µg/kg), group D1.0 (dexmedetomidine 1.0 µg/kg). Time to extubation and tympanic temperature during and after operation were measured. Shivering was graded (0-3 scale) upon patients arrival to the PACU and every ten minutes thereafter up to forty minutes. Sedation and first rescue analgesic time at the PACU were evaluated. RESULTS: The incidence of shivering was significantly lower in group D0.75 and D1.0 than in group S (P < 0.05). There were significantly fewer patients with a shivering score of 2 or 3 in groups D0.75 and D1.0 than in group S (P < 0.05, P < 0.001). Extubation time was shorter in group S than in groups D0.75 and D1.0 (P < 0.05). Tympanic temperature at 40 minutes postoperatively in the recovery room was higher in group S than in the other dexmedetomidine groups (P < 0.05) Fewer patients required rescue analgesia in groups D0.75 and D1.0 than in group S (P < 0.001), and the time to rescue analgesia was longer in group D1.0 than in group S (P < 0.001). Modified Observer's Assessment of Alertness/Sedation (MOAA/S) at arrival in the PACU was lower in all dexmedetomidine groups than in group S (P < 0.05). CONCLUSIONS: Our results suggest that dexmedetomidine 0.75 or 1.0 µg/kg provides effective prophylaxis against postoperative shivering as well as an analgesic effect. Though potential for intraoperative requirement for atropine, sedation in the immediate recovery period and delayed extubation time with dexmedetomidine was noted, there were no major clinical impacts on the overall recovery from anesthesia.

Comparison between dexmedetomidine and remifentanil for controlled hypotension and recovery in endoscopic sinus surgery.

OBJECTIVES: We compared the efficacy of dexmedetomidine and remifentanil hydrochloride in intraoperative field conditions and recovery during endoscopic sinus surgery. METHODS: Sixty-six patients (American Society of Anesthesiologists physical status I and II) scheduled for elective endoscopic sinus surgery were enrolled in this prospective, double-blinded, randomized study. The patients were randomly assigned to two groups. Propofol, 2 to 2.5 mg/kg, was administered to both groups to induce anesthesia, which was maintained with desflurane. One group received dexmedetomidine 1 microg/kg over 10 minutes at anesthesia induction, followed by 0.4 to 0.8 microg/kg per hour infusion during maintenance, whereas the other group received remifentanil 1 microg/kg over 1 minute at anesthesia induction, followed by 0.2 to 0.4 microg/kg per minute infusion during maintenance. Surgical conditions, hemodynamic parameters, intraoperative blood loss, time to extubation, sedation, and pain in the postanesthesia care unit (PACU) were recorded. RESULTS: There were no significant differences between the two groups with respect to surgical field conditions, blood loss, or extubation time. The sedation score (Modified Observer's Assessment of Alertness/Sedation) in the PACU was significantly lower in the dexmedetomidine group than in the remifentanil group (p < 0.001). No differences were found in total blood loss, surgical field conditions, hemodynamic parameters, time to extubation, or pain in the PACU when the two groups were compared (p > 0.05). CONCLUSIONS: Although remifentanil and dexmedetomidine both enabled hypotensive anesthesia and good intraoperative fields for endoscopic sinus surgery, recovery was faster with remifentanil than with dexmedetomidine in the immediate postoperative period.

Beyond Pathogen Filtration: Possibility of Smart Masks as Wearable Devices for Personal and Group Health and Safety Management.

Face masks are an important way to combat the COVID-19 pandemic. However, the prolonged pandemic has revealed confounding problems with the current face masks, including not only the spread of the disease but also concurrent psychological, social, and economic complications. As face masks have been worn for a long time, people have been interested in expanding the purpose of masks from protection to comfort and health, leading to the release of various "smart" mask products around the world. To envision how the smart masks will be extended, this paper reviewed 25 smart masks (12 from commercial products and 13 from academic prototypes) that emerged after the pandemic. While most smart masks presented in the market focus on resolving problems with user breathing discomfort, which arise from prolonged use, academic prototypes were designed for not only sensing COVID-19 but also general health monitoring aspects. Further, we investigated several specific sensors that can be incorporated into the mask for expanding biophysical features. On a larger scale, we discussed the architecture and possible applications with the help of connected smart masks. Namely, beyond a personal sensing application, a group or community sensing application may share an aggregate version of information with the broader population. In addition, this kind of collaborative sensing will also address the challenges of individual sensing, such as reliability and coverage. Lastly, we identified possible service application fields and further considerations for actual use. Along with daily-life health monitoring, smart masks may function as a general respiratory health tool for sports training, in an emergency room or ambulatory setting, as protection for industry workers and firefighters, and for soldier safety and survivability. For further considerations, we investigated design aspects in terms of sensor reliability and reproducibility, ergonomic design for user acceptance, and privacy-aware data-handling. Overall, we aim to explore new possibilities by examining the latest research, sensor technologies, and application platform perspectives for smart masks as one of the promising wearable devices. By integrating biomarkers of respiration symptoms, a smart mask can be a truly cutting-edge device that expands further knowledge on health monitoring to reach the next level of wearables.

Advanced glycation end products downregulate glucokinase in mice.

BACKGROUND: Glucokinase, the enzyme that catalyses the conversion of glucose to G-6-P, plays a key role in glucose metabolism. AGEs are implicated in diabetic complications. A previous study reported that AGEs decreased ß-cell function through inhibition of cytochrome c oxidase and adenosine triphosphate synthesis. This study investigated the effects of AGEs on glucokinase and islet function. METHODS: Six-month-old male C57BL6 mice were divided into bovine serum albumin (BSA) and AGE-BSA groups. BSA (200 µg/g) and AGE-BSA (60 U/g) were administered intraperitoneally twice daily. After 2 weeks, serum AGE levels were measured, oral glucose tolerance test was performed, and insulin levels during the oral glucose tolerance test were determined. Glucokinase protein expression level and activity were measured in pancreatic islets. RESULTS: We observed that the normal mice (C57/BL6) treated for 2 weeks with AGE-BSA showed impaired glucose tolerance and decrease in acute insulin release. Glucokinase activity in islets from the AGE-BSA-treated mice was significantly inhibited and accompanied by blunted response of islets to high glucose stimulation. Moreover, in vitro experiments showed that glucokinase protein expression was decreased, its activity was inhibited, and islet function was decreased. GKA partially restored glucokinase activity and islet function caused by AGEs. CONCLUSIONS: We concluded that AGEs inhibited glucokinase activity, leading to islet dysfunction in mouse pancreatic islets.

The small molecule kobusone can stimulate islet ß-cell replication in vivo.

OBJECTIVE: To investigate the ability of kobusone to reduce high glucose levels and promote ß-cell proliferation. METHODS: Four-week-old female db/db mice were assigned to the kobusone (25 mg/kg body weight, intraperitoneally twice a day) or control group (same volume of PBS). Glucose levels and body weight were measured twice a week. After 6 weeks, intraperitoneal glucose tolerance tests and immunohistochemical studies were performed, and insulin levels were determined. The expression of mRNAs involved in cell proliferation, such as PI3K, Akt, cyclin D3 and p57Kip2, was measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR). RESULTS: Kobusone reduced blood glucose levels after 3 weeks and more strongly increased serum insulin levels than the vehicle. Immunohistochemistry illustrated that kobusone increased 5-bromo-2'-deoxyuridine incorporation into islet ß-cells, suggesting that it can stimulate islet ß-cell replication in vivo. RT-qPCR indicated that kobusone upregulated the mRNA expression of PI3K, Akt, and cyclin D3 and downregulated that of p57Kip2. CONCLUSION: Our findings suggest that kobusone is a potent pancreatic islet ß-cell inducer that has the potential to be developed as an anti-diabetic agent.

Association of thymic stromal lymphopoietin gene -847C>T polymorphism in generalized vitiligo.

Thymic stromal lymphopoietin (TSLP) induces naïve CD4+ T cells to produce Th2 cytokines. In addition, to low production of Th2 cytokines, strong Th1 response, which plays an important role in vitiligo development, has been induced by blockade of TSLP or TSLP receptor. This study examined whether a functional TSLP polymorphism was associated with vitiligo. One hundred and sixty Korean patients with vitiligo and 568 healthy Korean individuals were examined for the four SNPs of TSLP gene. Luciferase activity was measured for promoter assay. The genotype and allele frequencies of -847C>T polymorphism were lower in vitiligo patients compared with the controls, whereas those of wild type were higher (P = 0.004, P = 0.017 respectively). None the less, the promoter activity of -847C decreased significantly (P = 0.013) compared with -847T, expecting lower TSLP mRNA levels in the polymorphism. Collectively, C allele at the TSLP -847C>T polymorphism may increase susceptibility to generalized vitiligo through decreasing TSLP mRNA expression levels.

Comparative study of the influence of room-temperature and warmed fluid irrigation on body temperature in arthroscopic shoulder surgery.

PURPOSE: The purpose of this study was to evaluate the effect of irrigation fluid temperature on body temperature and other variables, and to determine their correlations. METHODS: A prospective randomized study was performed of 50 patients undergoing arthroscopic shoulder surgery who received irrigation fluid either with room temperature or warmed to 37 degrees C to 39 degrees C. Core body temperature was checked at regular intervals, and additional variables, such as length of anesthesia and surgery, amount of irrigation fluid and intravenous fluid used, amount of bleeding, weight gain, and postoperative pain were collected during surgery and postoperatively. RESULTS: The final core body temperature was 35.5 +/- 0.3 degrees C in the room-temperature fluid group and 36.2 +/- 0.3 degrees C in the warmed fluid group (P < .001). The temperature drop was 0.86 +/- 0.2 degrees C in the room-temperature fluid group and 0.28 +/- 0.2 degrees C in the warmed fluid group (P < .001). Hypothermia occurred in 91.3% of patients in the room-temperature fluid group; the incidence of hypothermia was much lower in the warmed fluid group (17.4%; P < .001). Of the variables measured, the patient's age and amount of irrigation fluid used correlated with core body temperature in the room-temperature fluid group. No variables correlated with core body temperature in the warmed fluid group. CONCLUSIONS: Hypothermia occurred more often in shoulder arthroscopic surgery with room-temperature fluid irrigation than with warmed fluid irrigation. The patient's age and amount of irrigation fluid used correlate with core body temperature when using room-temperature irrigation fluid. The use of warm irrigation fluid during arthroscopic shoulder surgery decreases perioperative hypothermia, especially in elderly patients. LEVEL OF EVIDENCE: Level I, therapeutic randomized controlled trial.

Changes of intraocular pressure and ocular perfusion pressure during controlled hypotension in patients undergoing arthroscopic shoulder surgery: A prospective, randomized, controlled study comparing propofol, and desflurane anesthesia.

PURPOSE: The aim of the present study is to evaluate the effects of deliberate hypotensive anesthesia on intraocular pressure (IOP) and ocular perfusion pressure (OPP) and compare the effects of propofol total intravenous anesthesia (TIVA) and desflurane anesthesia on IOP and OPP. METHODS: A total of 50 patients undergoing arthroscopic shoulder surgery in the lateral decubitus position were randomized to receive desflurane or propofol anesthesia. Mean arterial pressure (MAP) was maintained in the range of 60-75 mm Hg during hypotensive anesthesia. IOP was measured using a handheld tonometer at 7 time points: before induction (T1, baseline); immediately after endotracheal intubation (T2); 10 minutes after position change to lateral decubitus (T3); 10, 30, and 50 minutes after the start of hypotensive anesthesia (T4-T6); and at the end of surgery (T7). RESULTS: MAP decreased about 35% to 38% during hypotensive anesthesia. Compared to baseline values, the IOP at T6 in dependent and non-dependent eyes decreased by 0.43 and 2.74 mm Hg, respectively in desflurane group; 3.61 and 6.05 mm Hg, respectively in the propofol group. IOP of both eyes in the propofol group was significantly lower than in the desflurane group from T2 to T7. OPP of both eyes in both groups was significantly lower than at baseline, except at T2 in the desflurane group. OPP of both eyes in the propofol group was significantly higher than that in the desflurane group at T5 and T6. CONCLUSIONS: Hypotensive anesthesia reduced IOP and OPP, but propofol TIVA maintained higher OPP than desflurane anesthesia. These findings suggest that propofol TIVA can help mitigate the decrease of OPP during hypotensive anesthesia.

Optimal dose of perineural dexmedetomidine for interscalene brachial plexus block to control postoperative pain in patients undergoing arthroscopic shoulder surgery: A prospective, double-blind, randomized controlled study.

BACKGROUND: Adjuvant perineural dexmedetomidine can be used to prolong the analgesic effect of interscalene brachial plexus block (ISB). We investigated the optimal dose of dexmedetomidine in ISB for postoperative analgesia in patients undergoing arthroscopic shoulder surgery. METHODS: One hundred patients scheduled for elective shoulder arthroscopic surgery were enrolled in this randomized, double-blind study. Ultrasound-guided ISB was performed before general anesthesia using 22 mL of ropivacaine 0.5% combined with 1, 1.5, or 2 µg/kg of dexmedetomidine (group D1, D2, and D3, respectively) or with normal saline as a control (group R, n = 25 per group). The primary outcome was the duration of analgesia (DOA), numeric pain rating scale (NRS), and consumption of additional analgesics during 36 h after ISB. Secondary outcome included durations of motor and sensory block (DOM and DOS), hemodynamic variables and sedation and dyspnea scores. RESULTS: Ninety-seven patients completed the study. The DOS, DOM, and DOA were significantly longer in the dexmedetomidine groups than in group R. The DOA was significantly longer in group D3 than in groups D1 (P = .026) and D2 (P = .039). The DOA was 808.13 ±â€Š179.97, 1032.60 ±â€Š288.14, 1042.04 ±â€Š188.13, and 1223.96 ±â€Š238.06 min in groups R, D1, D2, and D3, respectively. The NRS score was significantly higher in group R than in the dexmedetomidine groups 12 h after ISB (P < .001) and significantly lower in group D3 than in the other groups 18 h after ISB (P = .02). The incidence of hypotension was higher in groups D2 and D3 than in group R during surgery (P = .008 and P = .011, respectively). There were no significant differences in consumption of rescue analgesics, sedation, and dyspnea scores between the study groups. CONCLUSION: Perineural dexmedetomidine 2 µg/kg could be the optimal dose in ISB for arthroscopic shoulder surgery in that it provides an adequate DOA. However, this dose was associated with increased risk of hypotension.

Activation of Ternary Transition Metal Chalcogenide Basal Planes through Chemical Strain for the Hydrogen Evolution Reaction.

Invited for this month's cover are collaborators from the Institute for Basic Science (South Korea), Sungkyunkwan University (South Korea), and Banaras Hindu University (India). The cover picture shows the two-dimensional layered transition metal chalcogenide for efficient hydrogen evolution. Read the full text of the article at 10.1002/cplu.201700164.

Activation of Ternary Transition Metal Chalcogenide Basal Planes through Chemical Strain for the Hydrogen Evolution Reaction.

Catalytically inactive basal planes pose challenges for the efficient hydrogen evolution reaction (HER) in two-dimensional (2 D) transition metal chalcogenide (TMC) nanosheets. Herein, a new hybrid structure is reported in which zero-dimensional TMC nanodots (NDs) are decorated on the basal planes of 2 D nanosheets of TMCs to enhance their catalytic activity towards the HER process. A novel process is developed to fabricate a hybrid Cu2 MoS4 (2 D ternary transition metal chalcogenide Cu2 MoS4 nanosheets)/MoSe2 (0 D binary transition metal chalcogenide MoSe2 ND) nanostructure by controlling the size of the MoSe2 NDs to enhance the HER activity. In acidic media, this optimal hybrid Cu2 MoS4 /MoSe2 nanostructure achieves excellent catalytic activity for HER, which exhibits a low overpotential of 166 mV at a current density of 10 mA cm-2 , which corresponds to a Tafel slope of 74.7 mV dec-1 . In addition, the synthesized hybrid nanostructure shows excellent stability when under acidic medium for 16 h of continuous electrolysis. Therefore, it is suggested that our strategy may open a new path for the design of hybrid nanostructures by using ternary transition metal chalcogenides (TTMCs) with binary transition metal chalcogenides (BTMCs) for alternative non-noble metal catalysts towards HER.

Surface-Enhanced Raman Scattering and Fluorescence-Based Dual Nanoprobes for Multiplexed Detection of Bacterial Pathogens.

Surface-enhanced Raman scattering (SERS)-based biosensing has been of growing interest for the detection of bacterial pathogens. Moreover, fluorescence (FL)-based bioimaging is also useful in that it is rapid, nearly non-destructive and has high sensitivity. In this study, for the first time, we report the preparation of dual nanoprobes based on both SERS and FL. These probes comprise hierarchical nanostructures with metallic nanoparticle clusters (MNPCs). In combination with magnetic beads (MBs), the probes were used for fast and multiplexed detection of bacterial pathogens. Both MNPCs with different Raman dyes and two sets of FL dyes were simultaneously encapsulated within polymeric nanoparticles using electrohydrodynamic (EHD) jetting and chemically stabilized. Two different sets of monoclonal antibodies (mAbs) against two kinds of bacterial pathogens, Escherichia coli and Francisella tularensis, were separately conjugated with the dual nanoprobes and the MBs. Sandwich-type immunocomplexes composed of SERS-FL dual nanoprobes, pathogens, and MBs were formed in the presence of E. coli and F. tularensis, and a linear correlation was observed between Raman intensity and pathogen concentration in the range of 102­106 cells/mL; the limit of detection was less than 102 cells/mL. Also, selective sandwich-type immunocomplexes against the pathogens were successfully imaged by FL signals at 514 nm and 633 nm wavelength for excitation. In conclusion, excellent capability of fast imaging and multiplexed detection of bacterial pathogens was achieved using a new class of SERS-FL dual nanoprobes, providing a powerful tool for qualitative and quantitative multiplexed biodetection of pathogens.

Spontaneous C1-2 cerebrospinal fluid leak treated with a targeted cervical epidural blood patch using a cervical epidural Racz catheter.

A 39-year-old woman with no history of trauma or meningitis presented to the neurology department of our hospital with an occipital headache, neck pain, nausea, and dizziness that had worsened during the previous month. The headache worsened when sitting or standing and partially regressed when lying down. She was diagnosed with spontaneous intracranial hypotension (SIH) and received conservative management. After failing to respond to conservative management, she underwent an autologous epidural blood patch (EBP) at the T7-8 level. The headache and associated symptoms did not improve after the procedure. Magnetic resonance (MR) myelography suggested a cerebrospinal fluid leakage at the C1-2 level resulting in intracranial hypotension. An 18-gauge Tuohy needle was inserted at the T1-2 interlaminal level using a paramedian approach under fluoroscopic guidance. The cervical epidural Racz catheter was threaded through the Tuohy needle up to the cervical spine and the catheter tip was confirmed to be at the right cervical 1-2 site on an anteroposterior (AP) view. Five mL of autologous blood was injected into the epidural space through the cervical epidural Racz catheter. Her occipital headache and associated symptoms gradually disappeared after the procedure. Seven days later the headache was largely resolved and she was discharged. Follow-up magnetic resonance imaging (MRI) showed the disappearance of abnormal radiological features associated with intracranial hypotension. She currently remains symptom free for 9 months. Delivery of autologous blood patch via a cervical epidural Racz catheter inserted from the upper thoracic spine can be a safe and effective method for patients with SIH due to cerebrospinal fluid (CSF) leakage in the upper cervical spine.

Optimal dose of dexmedetomidine for attenuating cardiovascular response during emergence in patients undergoing total laparoscopic hysterectomy.

OBJECTIVE: To investigate the optimal dose of dexmedetomidine for attenuating the haemodynamic response during emergence from anaesthesia. METHODS: Patients undergoing laparoscopic total hysterectomy were randomly allocated to receive 0.9% normal saline (control group) or dexmedetomidine (0.5 µg/kg, 0.75 µg/kg or 1.0 µg/kg 30 min) before extubation. Heart rate, systolic and diastolic arterial pressure and extubation time were measured before drug administration, immediately after the end of drug administration, 10 min after the end of drug administration, immediately after extubation and 5 min after extubation. RESULTS: A total of 120 patients were included in the study (30 per group). Systolic and diastolic arterial pressure and heart rate after drug administration were significantly lower in all three dexmedetomidine groups compared with controls. Extubation times in the 0.75 and 1.0 µg/kg dexmedetomidine groups were significantly longer than in the control group. CONCLUSION: Intravenous infusion of 0.5 µg/kg dexmedetomidine 30 min before the end of surgery attenuated the haemodynamic responses during emergence without prolonging the extubation time. Dexmedetomidine doses higher than 0.5 µg/kg did not exert additional positive effects on cardiovascular responses, but did significantly prolong the extubation time.

The potential role of VPREB1 gene copy number variation in susceptibility to rheumatoid arthritis.

Although the etiology of rheumatoid arthritis (RA) remains unknown, it has been widely suggested that RA has a genetic background. In humans, a copy number loss of 22q11.2, a region harboring the VPREB1 gene, has been suggested to be associated with several immunologic disorders, but there has been no study on the copy number variation (CNV) of the VPREB1 and its potential association with RA. Here, we explored the association between the RA and the CNV of the VPREB1 gene by performing genomic quantitative PCR and quantification of B cell subsets in RA patients and controls. The proportion of the individuals with <2 copies of the VPREB1 gene was significantly higher in the patient group than that in the controls (12.9% vs 0.9%, p<0.0001), while that of the individuals with >2 copies was lower in the patient group than that in the controls (1.7% vs 18.9%, p<0.0001). The odds ratio (OR) of the individuals with <2 copies was significantly higher compared with the odds ratio of those individuals with 2 copies (OR=12.1, 95% confidence interval (CI) 2.8-51.6). Likewise, the OR of the individuals with >2 copies was significantly lower than the OR of those individuals with 2 copies (OR=0.09, 95% CI 0.03-0.3). We also found that the proportion of CD21⁻CD23⁻ B cells was significantly higher in the RA patients compared with that of the controls (11.9% vs 5.7%, p=0.002), but the proportion of CD21+CD23+ cells was significantly lower in the RA patients (26.2% in RA vs 34.9% in the controls, p=0.005). To the best of our knowledge, this is the first evidence showing the association between a low copy number of the VPREB1 gene and RA, and this may help understanding the pathogenesis of RA and other autoimmune disorders.