544 research outputs found
A solvent-free Diels-Alder reaction of graphite into functionalized graphene nanosheets
A solvent-free Diels-Alder reaction was carried out by heating a mixture of graphite and a typical dienophile, maleic anhydride (MA) or maleimide (MI), in a sealed glass ampoule of argon. The functionalization of graphite with dienophiles was confirmed by various characterization techniques, suggesting the efficient functionalization and delamination of graphite into a few layers of graphitic nanosheets.close0
Unified Hierarchical Relationship Between Thermodynamic Tradeoff Relations
Recent years have witnessed a surge of discoveries in the studies of
thermodynamic inequalities: the thermodynamic uncertainty relation (TUR) and
the entropic bound (EB) provide a lower bound on the entropy production (EP) in
terms of nonequilibrium currents; the classical speed limit (CSL) expresses the
lower bound on the EP using the geometry of probability distributions; the
power-efficiency (PE) tradeoff dictates the maximum power achievable for a heat
engine given the level of its thermal efficiency. In this study, we show that
there exists a unified hierarchical structure encompassing all of these bounds,
with the fundamental inequality given by a novel extension of the TUR (XTUR)
that incorporates the most general range of current-like and state-dependent
observables. By selecting more specific observables, the TUR and the EB follow
from the XTUR, and the CSL and the PE tradeoff follow from the EB. Our
derivations cover both Langevin and Markov jump systems, with the first proof
of the EB for the Markov jump systems and a more generalized form of the CSL.
We also present concrete examples of the EB for the Markov jump systems and the
generalized CSL.Comment: 19 pages, 4 figure
Age group characteristics of clinical features and use of epinephrine in children with anaphylaxis who visited the emergency department
Purpose Diagnosis of anaphylaxis depends on clinical manifestations and a high index of suspicion, and a misdiagnosis can lead to a preventable death. We aimed to investigate age group characteristics of clinical features and epinephrine use in children with anaphylaxis who visited the emergency department (ED). Methods We performed a retrospective chart review of 138 children who visited a tertiary care hospital ED from January through December 2018, and were discharged with anaphylaxis as the diagnosis. Anaphylaxis was defined according to the National Institutes of Allergy and Infectious Disease criteria. The children were divided into 4 age groups; infants (< 1 year), preschoolers (1-5 years), schoolers (6-11 years), and adolescents (12-18 years). Clinical features and epinephrine use were compared among the age groups. Results Of the 138 children with presumed anaphylaxis, 108 met the criteria. The most common cause was food (74%), followed by drugs (10.2%). Epinephrine was used in 82 children (75.9%). The infants and preschoolers reported less frequent cardiovascular symptoms (0%-3.6% vs. 26.5%, P = 0.020) and epinephrine use (33.3%-70.9% vs. 91.2%, P = 0.037) compared to the adolescents. The former 2 age groups reported food as triggers more frequent, and often reported food-associated and respiratory or gastrointestinal symptoms. Conclusion Infants and preschoolers with anaphylaxis may undergo less frequent cardiovascular symptoms and epinephrine use compared to adolescents. This feature prompts to increased epinephrine use in the former age groups even without age-adjusted hypotension
Ectopic adrenal gland tissue in the left ovary of an elderly woman: a case report
Ectopic adrenal gland in the ovary is very rare case, and even more rarer in older women. We reported a case of ectopic adrenal tissue as an incidental finding in left ovary from a 68-year-old woman. She presented with bearing down sensation due to uterine prolapse for 5 years. Upon physical examination, uterine prolapse grade III, cystocele, and rectocele were observed. Ultrasonography findings showed 0.69 cm intramural myoma, and no specific findings were found in the bilateral adnexae. She underwent a total laparoscopic hysterectomy, bilateral salpingo-oophorectomy, and anterior-posterior repair. The final pathologic diagnosis of the case was ectopic adrenal gland tissue in the left ovary and uterine leiomyoma. No eventful reactions were observed during hospitalization and after discharge. Although ectopic adrenal gland rarely occurs in elderly women and in the pelvic ovaries, it has a risk of neoplastic transformation and accompanying germ cell tumor and sex cord tumor. Hence, if the ectopic adrenal gland tissue is suspected during surgery, the tissue should be removed. Additionally, by closely examining the contralateral ovary, determining whether other lesions are suspected is necessary. If the other lesions including germ cell tumor or sex cord tumor are suspected, a biopsy of the contralateral ovarian tissue should be performed. Thus, gynecologists must have knowledge about ectopic adrenal gland tissues
Non-invasive cortical stimulation improves post-stroke attention decline
Purpose: Attention decline after stroke is common and hampers the rehabilitation process, and non-invasive transcranial direct current stimulation (tDCS) has the potential to elicit behavioral changes by modulating cortical excitability. The authors tested the hypothesis that a single session of non-invasive cortical stimulation with excitatory anodal tDCS applied to the left dorsolateral prefrontal cortex (DLPFC) can improve attention in stroke patients. Methods: Ten patients with post-stroke cognitive decline (MMSE 0.05). Changes in reaction times were comparable for the two stimulations (P > 0.05). Conclusion: Non invasive anodal tDCS applied to the left DLPFC was found to improve attention versus sham stimulation in stroke patients, which suggests that non-invasive cortical intervention could potentially be used during rehabilitative training to improve attention.This research was supported by a grant from
Seoul National University College of Medicine (Grant
No. 800-20060236) to N.J. Paik, and by a grant from
the Korean Geriatric Society to E.K. Kang.Monti A, 2008, J NEUROL NEUROSUR PS, V79, P451, DOI 10.1136/jnnp.2007.135277Priori A, 2008, CEREB CORTEX, V18, P451, DOI 10.1093/cercor/bhm088Kuo MF, 2008, NEUROPSYCHOLOGIA, V46, P2122, DOI 10.1016/j.neuropsychologia.2008.02.023Coulthard E, 2006, CURR OPIN NEUROL, V19, P613Boggio PS, 2006, J NEUROL SCI, V249, P31, DOI 10.1016/j.jns.2006.05.062Gandiga PC, 2006, CLIN NEUROPHYSIOL, V117, P845, DOI 10.1016/j.clinph.2005.12.003Fregni F, 2005, EXP BRAIN RES, V166, P23, DOI 10.1007/s00221-005-2334-6Hummel F, 2005, BRAIN, V128, P490, DOI 10.1093/brain/awh369DEVINSKY O, 2004, NEUROLOGY COGNITIVENitsche MA, 2003, J COGNITIVE NEUROSCI, V15, P619, DOI 10.1162/089892903321662994McDowd JM, 2003, J GERONTOL B-PSYCHOL, V58, pP45Hikosaka O, 2002, CURR OPIN NEUROBIOL, V12, P217Aranda D, 2001, REV NEUROLOGIA, V32, P10Nitsche MA, 2000, J PHYSIOL-LONDON, V527, P633McNevin NH, 2000, PHYS THER, V80, P373DESPOSITO M, 1998, BRAIN RES COGN BRAIN, V7, P1TATEMICHI TK, 1994, J NEUROL NEUROSUR PS, V57, P202
Characteristics and surgical outcomes of cleft palate in kabuki syndrome: a case series of 11 patients
Objective
A significant number of patients with KS have cleft palate (CP) or submucous cleft palate (SMCP) and show delayed speech development. However, few reports have discussed the characteristics of CP in KS and the outcomes of postoperative speech development. The purpose of this study was to investigate the characteristics and surgical outcomes of CP in patients with KS, and to discuss the importance of the diagnosis of CP or SMCP.
Methods
We conducted a retrospective study on patients with clinically diagnosed KS who underwent palatoplasty. Clinical and surgical data were collected from patients medical records, and velopharyngeal function was evaluated using nasopharyngoscopy and speech analysis.
Results
In 11 cases, 5 patients had CP (45.5%) and 6 had SMCP (54.5%). Four patients who were genetically tested had a pathogenic variant of KMT2D. Seven of nine patients (77.8%) who underwent conventional palatoplasty showed velopharyngeal insufficiency and hypernasality. All patients who underwent pharyngeal flap surgery achieved velopharyngeal competency. Statistical analysis revealed a statistically significant difference in postoperative results between non-syndromic and KS patients.
Conclusion
Patients with SMCP may be more common than previously reported. The results showed that it is difficult to produce optimal results with conventional palatoplasty; therefore, pharyngeal flap surgery should be considered as a treatment to obtain favorable results. Pharyngeal flap surgery in patients with KS should be carefully designed based on speech evaluation and nasopharyngoscopic findings
Characterization of eight novel proteins with male germ cell-specific expression in mouse
<p>Abstract</p> <p>Background</p> <p>Spermatogenesis and fertilization are highly unique processes. Discovery and characterization of germ cell-specific genes are important for the understanding of these reproductive processes. We investigated eight proteins encoded by novel spermatogenic cell-specific genes previously identified from the mouse round spermatid UniGene library.</p> <p>Methods</p> <p>Polyclonal antibodies were generated against the novel proteins and western blot analysis was performed with various protein samples. Germ cell specificity was investigated using testes from germ cell-less mutant mice. Developmental expression pattern was examined in testicular germ cells, testicular sperm and mature sperm. Subcellular localization was assessed by cell surface biotin labeling and trypsinization. Protein localization and properties in sperm were investigated by separation of head and tail fractions, and extractabilities by a non-ionic detergent and urea.</p> <p>Results</p> <p>The authenticity of the eight novel proteins and their specificity to spermatogenic cells were confirmed. In examining the developmental expression patterns, we found the presence of four proteins only in testicular germ cells, a single protein in testicular germ cells and testicular sperm, and three proteins in the testicular stages and mature sperm from the epididymis. Further analysis of the three proteins present in sperm disclosed that one is located at the surface of the acrosomal region and the other two are associated with cytoskeletal structures in the sperm flagellum. We name the genes for these sperm proteins Shsp1 (Sperm head surface protein 1), Sfap1 (Sperm flagellum associated protein 1) and Sfap2 (Sperm flagellum associated protein 2).</p> <p>Conclusion</p> <p>We analyzed eight novel germ cell-specific proteins, providing new and inclusive information about their developmental and cellular characteristics. Our findings will facilitate future investigation into the biological roles of these novel proteins in spermatogenesis and sperm functions.</p
Comparison of Operational Definition of Type 2 Diabetes Mellitus Based on Data from Korean National Health Insurance Service and Korea National Health and Nutrition Examination Survey
Background We evaluated the validity and reliability of the operational definition of type 2 diabetes mellitus (T2DM) based on the Korean National Health Insurance Service (NHIS) database. Methods Adult subjects (โฅ40 years old) included in the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2017 were merged with those from the NHIS health check-up database, producing a cross-sectional dataset. We evaluated the sensitivity, specificity, accuracy, and agreement of the NHIS criteria for defining T2DM by comparing them with the KNHANES criteria as a standard reference. Results In the study population (n=13,006), two algorithms were devised to determine from the NHIS dataset whether the diagnostic claim codes for T2DM were accompanied by prescription codes for anti-diabetic drugs (algorithm 1) or not (algorithm 2). Using these algorithms, the prevalence of T2DM was 14.9% (n=1,942; algorithm 1) and 20.8% (n=2,707; algorithm 2). Good reliability in defining T2DM was observed for both algorithms (Kappa index, 0.73 [algorithm 1], 0.63 [algorithm 2]). However, the accuracy (0.93 vs. 0.89) and specificity (0.96 vs. 0.90) tended to be higher for algorithm 1 than for algorithm 2. The validity (accuracy, ranging from 0.91 to 0.95) and reliability (Kappa index, ranging from 0.68 to 0.78) of defining T2DM by NHIS criteria were independent of age, sex, socioeconomic status, and accompanied hypertension or dyslipidemia. Conclusion The operational definition of T2DM based on population-based NHIS claims data, including diagnostic codes and prescription codes, could be a valid tool to identify individuals with T2DM in the Korean population
Systematic identification and integrative analysis of novel genes expressed specifically or predominantly in mouse epididymis
BACKGROUND: Maturation of spermatozoa, including development of motility and the ability to fertilize the oocyte, occurs during transit through the microenvironment of the epididymis. Comprehensive understanding of sperm maturation requires identification and characterization of unique genes expressed in the epididymis. RESULTS: We systematically identified 32 novel genes with epididymis-specific or -predominant expression in the mouse epididymis UniGene library, containing 1505 gene-oriented transcript clusters, by in silico and in vitro analyses. The Northern blot analysis revealed various characteristics of the genes at the transcript level, such as expression level, size and the presence of isoform. We found that expression of the half of the genes is regulated by androgens. Further expression analyses demonstrated that the novel genes are region-specific and developmentally regulated. Computational analysis showed that 15 of the genes lack human orthologues, suggesting their implication in male reproduction unique to the mouse. A number of the novel genes are putative epididymal protease inhibitors or ฮฒ-defensins. We also found that six of the genes have secretory activity, indicating that they may interact with sperm and have functional roles in sperm maturation. CONCLUSION: We identified and characterized 32 novel epididymis-specific or -predominant genes by an integrative approach. Our study is unique in the aspect of systematic identification of novel epididymal genes and should be a firm basis for future investigation into molecular mechanisms underlying sperm maturation in the epididymis
- โฆ