In this study, fluorescence of self-assembled multilayers (SAMs) of carbon dots (CDs) was found to be enhanced by graphene. The number of polyelectrolyte layers can be tuned to control the distance between CDs and graphene in SAMs. The enhanced fluorescence efficiency was found to be dependent on graphene concentration, degree of graphene reduction, and the distance between CDs and graphene surface. When graphene concentration and polyelectrolyte bilayer number were set to 0.005 mg mL−1 and 3 layers, respectively, fluorescence intensity of CDs could be increased up to 3.2 times. Tetracycline hydrochloride (Tc) could be detected by the established SAMs in the presence of graphene as the sensitivity was 2 orders higher than that of SAMs in the absence of graphene. Limit of detection of this sensing system was 0.9284 nM, which is 1–3 orders of magnitude lower than those of most of reported fluorescence sensors. This method could be successfully applied to detect trace Tc in milk samples.The fluorescence of carbon dots self-assembled multilayers (CDs SAMs) can be enhanced by graphene, the sensing sensitivity for tetracycline hydrochloride of CDs SAMs with graphene is two orders higher than that of SAMs without graphene.相似文献
Suppression of intratesticular testosterone (ITT) levels is required for spermatogenic recovery in rats after irradiation, but maintenance of peripheral testosterone (T) levels is important for many male functions. Considering the preservation of peripheral T while suppressing ITT, we tested the effects of a combination of a progestin, medroxyprogesterone acetate (MPA), plus T on spermatogenic recovery after irradiation, and compared its effects to those of T alone or T combined with estradiol (E2). Rats were given testicular irradiation (6 Gy) and treated during wk 3-7 after irradiation with MPA + T, or the individual steroids with or without GnRH antagonist (GnRH-ant), or GnRH-ant alone, or T + E2. Whereas GnRH-ant alone stimulated differentiation in 55% of tubules 13 wk after irradiation compared with 0% in irradiated-only rats, the addition of MPA reduced the percentage of tubules showing differentiation to 18%. However, T or MPA alone or the combination of the two induced germ cell differentiation in only 2-4% of tubules. In contrast, E2 stimulated differentiation in 88% of tubules, and T combined with E2 still resulted in differentiation in 30% of tubules. Although both MPA and E2 suppressed ITT levels to approximately 2% of control (2 ng/g testis), MPA was a less effective stimulator of spermatogenic recovery than E2 or GnRH-ant alone. MPA's function as a weak androgen was likely responsible for inhibiting spermatogenic recovery, as was the case for all other tested androgens. Thus, for clinical protection or restoration of spermatogenesis after radiation or chemotherapy by suppressing T production, MPA, at least in the doses used in the present study, is suboptimal. The combination of an estrogen with T appears to be most effective for stimulating such recovery. 相似文献
BACKGROUND & AIMS: Hepatic fibrosis due to chronic HBV infection has enormous socioeconomic impact. Besides strategies targeting virus elimination, prevention or reversal of liver fibrosis is amenable. Given the antifibrotic activity of interferon-gamma (IFN-gamma), a randomized open-labeled multicenter trial was initiated to test IFN-gamma in HBV infection. METHODS: HBsAg-positive patients with biopsy proven hepatic fibrosis (n = 99, stages 2-4, Scheuer criterion) were treated with diammone-glycyrrhizinate and potassium-magnesium aspartate. Sixty-six randomly assigned patients were treated with 50 mug IFN-gamma intramuscularly on a daily basis for 3 months and on alternate days the subsequent 6 months. Efficacy was evaluated by liver biopsy and serologic markers. RESULTS: Fifty-four patients in the IFN-gamma group and 29 patients in the control group completed the study. The hepatic fibrosis score was significantly reduced in 63% of IFN-gamma treated patients compared with 24.1% in the control group by using a semiquantitative scoring system evaluating both liver architecture and fibrotic deposits. Mean values for the total fibrosis score decreased from 13.8 +/- 5.8 to 10.1 +/- 5.1 in the IFN-gamma group (P = .0001), whereas they were unchanged in control subjects (13.2 +/- 6.8 vs 12.6 +/- 4.8, P = .937). The Scheuer system showed 12 out of 54 patients improved >or=1 stage(s) in the IFN-gamma group compared with 1 of 29 in the control group. Antifibrotic activity might be attributed to decreased transforming growth factor-beta signaling via phosphorylated Smad2 and reduced number of activated, alpha-smooth muscle actin positive hepatic stellate cells. CONCLUSIONS: IFN-gamma treatment for 9 months improves fibrosis scores in patients with chronic HBV infection most likely by antagonizing profibrogenic transforming growth factor-beta effects. 相似文献
Zusammenfassung
Hintergrund Die Implantation eines mechanischen Herzunterstützungssystem (MCSS) bei Patienten mit idiopathischer dilatativer Kardiomyopathie
im Endstadium kann zu einer Verbesserung der Herzfunktion führen und die Explantation des Systems erlauben. Wir berichten
über die Effekte der ventrikul?ren Entlastung auf die Herzfunktion, die humoralen Anti-β1-Adrenozeptor-Autoantik?rper (A-β1-AAK) sowie die myokardiale Fibrose.
Methoden 13 Patienten mit nichtisch?mischer dilatativer Kardiomyopathie im Endstadium (NYHA IV-D) erhielten ein monoventrikul?res (zw?lf
Patienten) oder ein biventrikul?res (ein Patient) Herzentlastungssystem. Alle hatten zur Zeit der Implantation einen Cardiac
Index <1,61·min−1·m2 K?rperoberfl?che, eine linksventrikul?re Auswurffraktion (LVEF) von <16%, einen linksventrikul?ren enddiastolischen Diameter
(LVEDd)>68 mm und einen positiven A-β1-AAK-Nachweis. Echokardiographische Auswertungen, Serumtests auf A-β1-AAK und histologische Untersuchungen hinsichtlich myokardialer Fibrose wurden vor und nach Implantation eines MCSS durchgeführt.
Ergebnisse Die durchschnittliche Unterstützungsdauer betrug 236±201 Tage (30 bis 794 Tage). Innerhalb dieses Zeitraums verbesserte sich
die LVEF von ≤15 auf im Durchschnitt 46% und der LVEDd von 74 auf 56 mm. Die A-β1-AAK waren nach im Mittel 11,7 Wochen im Serum nicht mehr nachweisbar. Ein Wiederanstieg konnte auch nach Explantation bei
keinem Patienten beobachtet werden. Ein hochpathologischer Fibroseanteil im Myokard war etwa ein Jahr nach Explantation ebenfalls
nicht mehr zu beobachten. Ein Patient dekompensierte sechs Monate nach Explantation und wurde daraufhin mit einem externen
monoventrikul?ren System unterstützt. Die nachfolgende Transplantation verlief erfolgreich. Ein weiterer Patient starb unmittelbar
nach Explantation an der Folge einer an?sthesiologischen Komplikation. Die mittlere Nachbeobachtungsdauer bei elf Patienten
nach Explantation betr?gt (Stand 31. 5. 1997) 12,6±9,77 Monate (drei bis 26 Monate). Kumulativ konnten 139 Patientenmonate
nachbeobachtet werden.
Schlu?folgerung Bei ausgew?hlten Patienten mit terminaler idiopathischer dilatativer Kardiomyopathie kann durch eine tempor?re mechanische
Herzunterstützung eine weitgehende Normalisierung der Herzfunktion erreicht werden. Die pr?operative myokardiale Fibrose ist
ein Jahr nach Explantation nicht mehr nachweisbar. Die A-β1-AAK verschwinden in der Phase der mechanischen Entlastung des Herzens und treten nach Explantation des Systems nicht mehr
auf. “Weaning” von der mechanischen Herzunterstützung kann eine Alternative zur Herztransplantation darstellen.
相似文献
OBJECTIVETo investigate the effect on pregnancy outcome of integrating a comprehensive management plan for patients with type 1 diabetes (T1D) into the World Health Organization universal maternal care infrastructure.RESEARCH DESIGN AND METHODSA comprehensive preconception-to-pregnancy management plan for women with T1D was implemented in 11 centers from 8 Chinese cities from 2015 to 2017. Sequential eligible pregnant women (n = 133 out of 137 initially enrolled) with T1D and singleton pregnancies attending these management centers formed the prospective cohort. The main outcome was severe adverse pregnancy outcome comprising maternal mortality, neonatal death, congenital malformations, miscarriage in the second trimester, and stillbirth. We compared pregnancy outcomes in this prospective cohort with two control groups with the same inclusion and exclusion criteria: a retrospective cohort (n = 153) of all eligible pregnant women with T1D attending the same management centers from 2012 to 2014 and a comparison cohort (n = 116) of all eligible pregnant women with T1D receiving routine care from 2015 to 2017 in 11 different centers from 7 cities.RESULTSThe rate of severe adverse pregnancy outcome was lower in the prospective cohort (6.02%) than in either the retrospective cohort (18.30%; adjusted odds ratio [aOR] 0.31 [95% CI 0.13–0.74]) or the contemporaneous comparison cohort (25.00%; aOR 0.22 [95% CI 0.09–0.52]).CONCLUSIONSThe substantial improvements in the prospective cohort are evidence of a potentially clinically important effect of the comprehensive management plan on pregnancy outcomes among Chinese pregnant women with pregestational T1D. This supports the development of similar approaches in other countries. 相似文献
Deficits in social skills are common in children with Autism Spectrum Disorder (ASD), and there is an urgent need for effective social skills interventions, especially for improving interactions with typically developing peers. This study examined the effects of a naturalistic behavioral social skills intervention in improving social initiations to peers through a randomized controlled trial. Analyses of multimethod, multi-informant measures indicated that children in the active group (SIMI) demonstrated greater improvement in the types of initiations which were systematically prompted and reinforced during treatment (i.e., behavior regulation). Generalization to joint attention and social interaction initiation types, as well as collateral gains in broader social functioning on clinician- and parent-rated standardized measures were also observed.