Female serotonin transporter-knockout rat: A potential model of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disease. Although visceral hypersensitivity (VH) and disturbed gastrointestinal motility are typical pathophysiological features of IBS, the pathological mechanisms underlying this disease remain unclear. Serotonin system abnormalities are considered to play an important role in the pathomechanisms of IBS. Here, we hypothesize that similar alterations, including VH and colonic motility, induced by serotonin transporter (SERT) knockout result from altered serotonin signaling. We sought to determine the molecular mechanism underlying VH and colonic dysmotility induced by SERT knockout. We found that female SERT (slc6a4)-knockout (KO; ie, slc6a4-/- ) rats exhibited lower pain pressure thresholds (PPTs) than wild-type (WT; ie, slc6a4+/+ ) rats in response to colorectal distension (CRD). Significantly increased fecal pellet output and reduced concentration of serum tryptophan were observed in the female SERT KO rats. The concentrations of 5-hydroxytryptamine (5-HT) in platelet-rich plasma (PRP) and serum in SERT KO rats were lower than those in WT rats, but the numbers of enterochromaffin cells (ECs) and the concentrations of 5-HT in colon of SERT KO rats were higher than those of WT rats. Finally, increased expression levels of 5-HT1B receptors, 5-HT2C receptors, 5-HT3A receptors, 5-HT3B receptors, 5-HT6 receptors, 5-HT7 receptors, and glycosylated dopamine transporters (DATs) were found in the female SERT KO rats. We concluded that alterations in the serotonin system induced by the knockout of slc6a4 might result in VH and accelerated gastrointestinal motility in female SERT KO rats, which can be used as an animal model of IBS.

The level and prevalence of depression and anxiety among patients with different subtypes of irritable bowel syndrome: a network meta-analysis.

BACKGROUND: Irritable bowel syndrome (IBS) is a very common functional bowel disorder. However, the difference of depression and anxiety comorbidities among different IBS subtypes is still not well evaluated. This study aims to investigate the difference in the level and prevalence of depression and anxiety among healthy controls and patients with different subtypes of IBS. METHODS: PubMed, EMBASE and the Cochrane library were searched systematically until August 17, 2020. Studies that investigated depression and/or anxiety levels or prevalence among different IBS-subtype patients measured at baseline or the same point were included. Network meta-analysis was conducted to analyze standardized mean difference (SMD) of anxiety and depression levels, and single arm meta-analysis was performed for prevalence of anxiety and depression among different IBS subtypes. RESULTS: Eighteen studies involving 7095 participants were included. Network meta-analyses results showed healthy controls had a lower level of depression than IBS with mixed symptoms of constipation and diarrhea (IBS-M) [SMD = - 1.57; 95% confidence interval (CI) - 2.21, - 0.92], IBS with constipation (IBS-C) (SMD = - 1.53; 95% CI - 2.13, - 0.93) and IBS with diarrhea (IBS-D)(SMD = - 1.41; 95% CI - 1.97, - 0.85), while no significant difference was found between IBS unclassified (IBS-U) and healthy controls (SMD = - 0.58; 95% CI - 2.15, 1.00). There was also no significant difference in the level of depression among different IBS subtypes patients. The results of anxiety were similar to depression. Ranking probability showed that IBS-M was associated with the highest level of depression and anxiety symptoms, followed by IBS-C/IBS-D and IBS-U. Single-arm meta-analysis showed IBS-C had the highest prevalence of depression (38%) and anxiety (40%), followed by IBS-D, IBS-M and IBS-U. CONCLUSION: The results indicated that IBS-M was more likely to be associated with a higher level of depression and anxiety, and the prevalence of depression and anxiety in IBS-C was highest. The psychological screening and appropriate psychotherapy are needed for patients with IBS-C, IBS-D and IBS-M instead of IBS-U.

Growth and Properties of Cl- Incorporated ZnO Nanofilms Grown by Ultrasonic Spray-Assisted Chemical Vapor Deposition.

Pure and Cl- incorporated ZnO nanofilms were grown by the ultrasonic spray-assisted chemical vapor deposition (CVD) method. The properties of the nanofilms were investigated. The effects of growth temperature and Cl- concentration on the crystal structure, morphology, and optical properties of the nanofilms were studied. Temperature plays an important role in the growth mode and morphology of the pure nanofilms. Preferential growth along the c-axis occurs only at modulating temperature. Lower temperature suppresses the preferential growth, and higher temperature suppresses the growth of the nanofilms. The morphologies of the nanofilms change from lamellar and spherical structures into hexagonal platelets, then into separated nanoparticles with an increase in the temperature. Incorporating Cl- results in the lattice contracting gradually along with c-axis. Grains composing the nanofilms refine, and the optical gap broadens with increasing of Cl- concentration in growth precursor. Incorporating Cl- could reduce oxygen vacancies and passivate the non-irradiated centers, thus enhancing the UV emission and suppressing the visible emission of ZnO nanofilms.

Growth and optical properties of ZnO/MgO core/shell nanoparticles.

Octylamine capped ZnO/MgO core/shell nanoparticles with different shell thickness were grown by thermolysis of metal organic precursors. The as-grown nanoparticles and subsequently annealed ones were characterized by X-ray diffractometer, transmission electron microscope, high resolution transmission electron microscope, and Micro Raman spectroscope. ZnMgO alloys and amorphous MgO formed on the surface of the ZnO cores in the as-grown core/shell nanoparticles. MgO crystalline formed after annealing at 430 degrees C for 2 h. ZnO cores have strong UV emission and weak visible emission. Growth of the shells could enhance the intensity of ZnO UV emission by 4.2 times. The thinner shells promote the core luminescence more efficiently than thicker ones. After being annealed in air at high temperatures, UV luminescence intensities of both pure core and core/shell nanoparticles degraded, while the luminescence of the core/shell nanoparticles with thinner shells degraded more obviously.

Synthesis and photocatalytic properties of CuO nanostructures.

CuO nanostructures were grown by decomposition of a mixture of Cu(CH3COO)2 x H2O and NaCl at different temperatures. The nanostructure properties were studied by X-ray diffractometer, scanning electron microscope and Raman spectroscope. Photodegradation activity of the nanostructures towards methyl orange was also examined. CuO spheres and hollow spheres composed of nanoparticles were obtained. CuO nanoparticle size increases with an increase in the growth temperature. More specifically, it increases slowly when the temperature was lower than 280 degrees C and increases dramatically in a higher temperature range. The degradation activity is sensitive to the nanostructure growth temperatures, but the degradation activity varies with the growth temperatures or the size of nanoparticles composing of nanospheres non-monotonously. The hollow spheres composed of nanoparticles grown at 280 degrees C show superior photocatalytic activity towards the degradation of methyl orange than that grown at lower and higher temperatures.

Properties of ZnO nanofilms formed at solution interfaces by nanoparticle oriention arrangement.

ZnO nanoparticles with the diameter of 11-33 nm were grown by decomposing a mixture of Zn(CH3COO)2 x 2H2O with NaCl and Li2CO3. Compact ZnO nanofilms were fabricated with the as-grown nanoparticles at the interfaces of the polar and non-polar solutions. The nanofilm properties were characterized by X-ray diffraction, scanning electron microscope, photoluminescence spectroscope and Raman spectroscope. Effects of the nanoparticle size on the nanofilm properties were studied. The nanoparticles with smaller sizes would align preferentially along [001] orientation during forming a film at an interface of two kinds of solutions. The nanofilm photoluminescence and Raman vibration are very sensitive to the sizes of the nanoparticles that form the nanofilms. 1LO vibration is enhanced in the nanofilms composed of nanoparticles with sizes smaller than 20 nm. The enhancement is attributed to the high density of deep level defects.

Growth and properties of ZnO films grown by the ultrasonic spray-assisted CVD.

ZnO films were successfully grown on the glass substrates employing an ultrasonic spray-assisted CVD method at 573-673 K. The optical properties, electrical characteristics and crystalline structures of the films were characterized. Effects of the growth temperatures on the film properties were studied. The film growth mode, morphology, transmittance, conductivity and emission properties are very sensitive to the growth temperatures. Growing at lower temperatures would improve both the preferential growth along c-axis and smoothness of the films. The conductivity and transmittance of the films grown at 573 K are also superior to that grown at higher temperatures. All films exhibit strong emission in the visible region and weak emission in UV region. However, the relative intensity of the UV emission to visible emission of the film grown at 573 K is obviously stronger than that grown at higher temperatures.

Oxygen Vacancy Induced Atom-Level Interface in Z-Scheme SnO2/SnNb2O6 Heterojunctions for Robust Solar-Driven CO2 Conversion.

The modulation of Z-scheme charge transfer is essential for efficient heterostructure toward photocatalytic CO2 reduction. However, constructing a compact hetero-interface favoring the Z-scheme charge transfer remains a great challenge. In this work, an interfacial Nb-O-Sn bond and built-in electric field-modulated Z-scheme Ov-SnO2/SnNb2O6 heterojunction was prepared for efficient photocatalytic CO2 conversion. Systematic investigations reveal that an atomic-level interface is constructed in the Ov-SnO2/SnNb2O6 heterojunction. Under simulated sunlight irradiation, the obtained Ov-SnO2/SnNb2O6 photocatalyst exhibits a high CO evolution rate of 147.4 µmol h-1 g-1 from CO2 reduction, which is around 3-fold and 3.3-fold of SnO2/SnNb2O6 composite and pristine SnNb2O6, respectively, and favorable cyclability by retaining 95.8% rate retention after five consecutive tests. As determined by electron paramagnetic resonance spectra, in situ Fourier transform infrared spectra, and density functional theory calculations, Nb-O-Sn bonds and built-in electric field induced by the addition of oxygen vacancies jointly accelerate the Z-scheme charge transfer for enhanced photocatalytic performance. This work provides a promising route for consciously modulating Z-scheme charge transfer by atomic-level interface engineering to boost photocatalytic performance.

Weakened Crystalline SnNb2 O6 for Enhanced Performance in Photocatalytic H2 Production and CO2 Reduction.

Low crystalline photocatalysts with unsaturated active sites, such as oxygen vacancy (Ov ), is reported to exhibit enhanced adsorption and activation of oxygen-containing small molecules, such as H2 O and CO2 , thus boosting the activity in photocatalytic H2 evolution and CO2 reduction. However, numerous low-crystalline photocatalysts show unsatisfactory stability due to the easily repaired surface Ov . Herein, three SnNb2 O6 with different crystallinity were prepared by hydrothermal approach with similar precursors. Compared with bulk SnNb2 O6 and ultra-thin layered SnNb2 O6 , low-crystalline SnNb2 O6 (SNA) exhibits optimal visible-light-driven evolution rates of H2 (86.04 µmol g-1 h-1 ) and CO from CO2 (71.97 µmol g-1 h-1 ), which is mainly ascribed to the fast separation of the photogenerated carriers and enhanced photoreduction power caused by the surface Ov . More importantly, the sharp decrease of photocatalytic activity of SNA after seven cycles is well restored by the hydrothermal treatment of recycled SNA, ascribed to the reactivated surface Ov with the recovered low-crystalline structure. These works thus offer a promising strategy for developing low-crystalline and amorphous photocatalysts with high activity and stability.

Shugan Decoction Alleviates Colonic Dysmotility in Female SERT-Knockout Rats by Decreasing M3 Receptor Expression.

BACKGROUND: Irritable bowel syndrome (IBS) is a functional gut disease characterized by visceral hypersensitivity and gut motor dysfunction. Serotonin (5-hydroxytryptamine, 5-HT) is an important enteric neurotransmitter. High levels of 5-HT aggravate IBS symptoms. The serotonin reuptake transporter (SERT) is a membrane-embedded transporter involved in IBS pathogenesis that plays an important role in regulating 5-HT signaling. AIM: We investigated whether gut motor function was altered in SERT-knockout (SERT-KO) rats. Additionally, we sought to determine whether Shugan decoction (SGD), a clinically experienced prescription for the treatment of IBS, exerts regulatory effects on intestinal motility in SERT-KO rats, and attempted to identify the mechanisms involved. METHOD: SERT-KO rats were produced by transcription activator-like effector nuclease (TALEN) technology. Fecal pellet output was measured for ten consecutive days to estimate distal colonic motility. Small intestinal motility was measured by charcoal-meal experiments. The colonic and small intestinal muscle contractile activities were measured by organ bath study. Western blot was used to analyze the muscarinic receptor expression in colon tissue. RESULT: Compared with that in wild-type (WT) rats, the defecation amount, amplitude of spontaneous contraction, and the tension of ACh-induced contraction of colonic longitudinal smooth muscle in SERT-KO rats were significantly increased. The expression of muscarinic receptor subtype-3 (M3R) in the colons of SERT-KO rats was also elevated. SGD can decrease defecation of SERT-KO rats. Moreover, SGD reduced the amplitude of spontaneous contraction, the frequency and tension of ACh-induced contraction of colonic longitudinal smooth muscle, and the expression of M3R in the colon in SERT-KO rats. CONCLUSIONS: SERT-KO rats showed increased defecation accompanied by enhanced colonic motility and M3R expression. The findings suggest that SGD modifies colonic dysmotility and reduces defecation in SERT-KO rats by down-regulating M3R expression in the colon.

Evolution of native defects in ZnO nanorods irradiated with hydrogen ion.

This work reports the study on the evolution of native defects in ZnO nanorods irradiated with hydrogen ion. ZnO nanorod arrays grown vertically on silicon substrates were irradiated by 180 keV H+ ions to a total fluence of 8.50 × 1015 ions/cm2. The X-ray diffraction spectra, photoluminescence spectra before and after irradiation and the real-time ionoluminescence spectra of the nanorod arrays during the irradiating process were measured. Formation and evolution of defects during H+ ion irradiation and effects of irradiation on the crystal structure and optical property were studied. Blue shift of exciton emission, shrink of lattice c and improvement of the crystallinity of ZnO nanorods after irradiation were observed. Simple surface passivation of the nanorods could improve the radiation resistance. Formation and evolution of the defects during H+ ion irradiation could be clarified into four stages and the related models are provided.

Detecting trap states in planar PbS colloidal quantum dot solar cells.

The recently developed planar architecture (ITO/ZnO/PbS-TBAI/PbS-EDT/Au) has greatly improved the power conversion efficiency of colloidal quantum dot photovoltaics (QDPVs). However, the performance is still far below the theoretical expectations and trap states in the PbS-TBAI film are believed to be the major origin, characterization and understanding of the traps are highly demanded to develop strategies for continued performance improvement. Here employing impedance spectroscopy we detect trap states in the planar PbS QDPVs. We determined a trap state of about 0.34 eV below the conduction band with a density of around 3.2 × 1016 cm-3 eV-1. Temperature dependent open-circuit voltage analysis, temperature dependent diode property analysis and temperature dependent build-in potential analysis consistently denotes an below-bandgap activation energy of about 1.17-1.20 eV.

Effects of doping and annealing on properties of ZnO films grown by atomic layer deposition.

Undoped and Al-doped ZnO films were synthesized by atomic layer deposition at 150°C and then annealed at 350°C in different atmospheres. Effects of doping and annealing on the film growth mode and properties were investigated. The undoped film has strong UV emission and weak Zn interstitial emission. Annealing introduces O vacancies, decreases Zn interstitials, and results in weakening and blue-shifting of the UV emission which is sensitive to annealing atmosphere. Al doping induces the film growing with its c-axis parallel to the substrate surface. It also introduces non-radiative centers and weakens the UV emission. Al doping widens the film bandgap, which has a quadratic dependence on Al content. Al doping decreases the film resistivity to 5.3 × 10(-3) Ω · cm. Annealing has little effect on photoluminescence of the doped films, but it degrades undoped and doped ZnO film conductivity dramatically; and the degradation depends on the annealing ambient.

Dual-protection of a graphene-sulfur composite by a compact graphene skin and an atomic layer deposited oxide coating for a lithium-sulfur battery.

A reduced graphene oxide (rGO)-sulfur composite aerogel with a compact self-assembled rGO skin was further modified by an atomic layer deposition (ALD) of ZnO or MgO layer, and used as a free-standing electrode material of a lithium-sulfur (Li-S) battery. The rGO skin and ALD-oxide coating worked as natural and artificial barriers to constrain the polysulfides within the cathode region. As a result, the Li-S battery based on this electrode material exhibited superior cycling stability, good rate capability and high coulombic efficiency. Furthermore, ALD-ZnO coating was tested for performance improvement and found to be more effective than ALD-MgO coating. The ZnO modified G-S electrode with 55 wt% sulfur loading delivered a maximum discharge capacity of 998 mA h g(-1) at a current density of 0.2 C. A high capacity of 846 mA h g(-1) was achieved after charging/discharging for 100 cycles with a coulombic efficiency of over 92%. In the case of using LiNO3 as a shuttle inhibitor, this electrode showed an initial discharge capacity of 796 mA h g(-1) and a capacity retention of 81% after 250 cycles at a current density of 1 C with an average coulombic efficiency higher than 99.7%.

An alumina stabilized ZnO-graphene anode for lithium ion batteries via atomic layer deposition.

Atomic layer deposition (ALD) was applied to deposit ZnO on graphene aerogel, and this composite was used as an anode material for lithium ion batteries. This electrode material was further modified by an ultrathin Al2O3 layer via ALD to stabilize its electrochemical stability. These two metal oxides were uniformly immobilized on graphene frameworks, and the Al2O3 coating strongly improved the electrochemical performances of ZnO-graphene aerogel composite anodes. Particularly, the composite with 10 ALD cycles of Al2O3 coating (denoted as ZnO-G-10) exhibited a high initial discharge capacity of 1513 mA h g(-1) and maintained a reversible capacity of 490 mA h g(-1) after 100 cycles at a current density of 100 mA g(-1). Furthermore, the capacity retention rate increased from 70% to 90% in comparison with its uncoated counterpart after 100 cycles. The ZnO-G-10 anode also showed good rate-capability, delivering a discharge capacity of 415 mA h g(-1) at 1000 mA g(-1). The improved electrochemical performance is attributed to the formation of an artificial solid electrolyte interphase layer, stabilizing ZnO and the electrolyte by preventing the aggregation of Zn/ZnO nanograins and the side reaction that would cause the degradation of anodes.