Evaluation of appendiceal mucinous neoplasms by curved linear-array echoendoscope: A preliminary study.

BACKGROUND: Preoperative diagnosis of appendiceal mucinous neoplasms is challenging, and there are few reports regarding the endosonographic characteristics of these neoplasms. AIM: To provide a retrospective assessment of the imaging features of appendiceal mucinous neoplasms using endoscopic ultrasound (EUS) by curved linear-array echoendoscope. METHODS: A database of all patients with appendiceal mucinous neoplasms who had received EUS examination at our hospital between January 2018 and July 2023 was retrospectively analyzed. The EUS characteristics and patients' clinical data were reviewed. RESULTS: Twenty-two patients were included in the study. The linear-array echoendoscope successfully reached the ileocecal region in every patient. In the endoscopic view, we could observe the protrusion in the appendiceal orifice in all patients. A volcano sign was observed in two patients, and an atypical volcano sign was seen in two patients. EUS showed that all 22 lesions were submucosal cystic hypoechoic lesions with clear boundaries. No wall nodules were observed, but an onion-peeling sign was observed in 17 cases. CONCLUSION: Linear-array echoendoscope is safe to reach the ileocecal region under the guidance of EUS. Image features on endoscopic and echoendosonograhic views could be used to diagnose appendiceal mucinous neoplasms.

Novel peroral cholangioscopy-directed lithotripsy using an ultraslim upper endoscope for refractory Mirizzi syndrome: A case report.

RATIONALE: Mirizzi syndrome (MS) is an uncommon condition characterized by common hepatic duct (CHD) compression by an impacted gallbladder or cystic duct stones or adjacent inflammation. To date, a standardized therapeutic strategy for MS has not been established yet, owing to its complex clinical presentation. Thus, researchers still have to develop new optimized approaches to solve this problem. Herein, we describe a patient with refractory MS who underwent a successful treatment by novel hybrid anchoring balloon-guided direct peroral cholangioscopy (POC) using an ultraslim endoscope. PATIENT CONCERNS: A 56-year-old man with a history of biliary stone was referred to our hospital for complaints of discomfort in the right upper quadrant of the abdomen and obstructive jaundice. Endoscopic retrograde cholangiopancreatography showed an 18-mm impacted stone at the level of the cystic duct, which compressed the CHD. The CHD had local stricture, with its upstream and intrahepatic bile duct dilation. DIAGNOSES: He was diagnosed with type I MS. INTERVENTIONS: Initially, the patient received an endoscopic major sphincterotomy. However, conventional stone extraction, including mechanical lithotripsy, was unsuccessful. Then, after signing the informed consent form for further treatment, he was successfully treated with novel hybrid anchoring balloon-guided direct POC. OUTCOMES: The patient had no operative complications and was discharged with cleared ducts. At the 3-year follow-up, he was asymptomatic. LESSONS: Our novel hybrid anchoring balloon-guided direct POC may be an effective alternative treatment approach for difficult gallbladder cases, such as refractory MS.

Imaging features of the initial chest thin-section CT scans from 110 patients after admission with suspected or confirmed diagnosis of COVID-19.

BACKGROUND: In December 2019, an outbreak of a novel coronavirus pneumonia, now called COVID-19, occurred in Wuhan, Hubei Province, China. COVID-19, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread quickly across China and the rest of the world. This study aims to evaluate initial chest thin-section CT findings of COVID-19 patients after their admission at our hospital. METHODS: Retrospective study in a tertiary referral hospital in Anhui, China. From January 22, 2020 to February 16, 2020, 110 suspected or confirmed COVID-19 patients were examined using chest thin-section CT. Patients in group 1 (n = 51) presented with symptoms of COVID-19 according to the diagnostic criteria. Group 2 (n = 29) patients were identified as a high degree of clinical suspicion. Patients in group 3 (n = 30) presented with mild symptoms and normal chest radiographs. The characteristics, positions, and distribution of intrapulmonary lesions were analyzed. Moreover, interstitial lesions, pleural thickening and effusion, lymph node enlargement, and other CT abnormalities were reviewed. RESULTS: CT abnormalities were found only in groups 1 and 2. The segments involved were mainly distributed in the lower lobes (58.3%) and the peripheral zone (73.8%). The peripheral lesions, adjacent subpleural lesions, accounted for 51.8%. Commonly observed CT patterns were ground-glass opacification (GGO) (with or without consolidation), interlobular septal thickening, and intralobular interstitial thickening. Compared with group 1, patients in group 2 presented with smaller lesions, and all lesions were distributed in fewer lung segments. Localized pleural thickening was observed in 51.0% of group 1 patients and 48.2% of group 2 patients. The prevalence of lymph node enlargement in groups 1 and 2 combined was extremely low (1 of 80 patients), and no significant pleural effusion or pneumothorax was observed (0 of 80 patients). CONCLUSION: The common features of chest thin-section CT of COVID-19 are multiple areas of GGO, sometimes accompanied by consolidation. The lesions are mainly distributed in the lower lobes and peripheral zone, and a large proportion of peripheral lesions are accompanied by localized pleural thickening adjacent to the subpleural region.

In vitro corrosion resistance of layer-by-layer assembled polyacrylic acid multilayers induced Ca-P coating on magnesium alloy AZ31.

Biodegradable magnesium (Mg)-based alloys have aroused great concern owing to their promising characteristics as temporary implants for orthopedic application. But their undesirably rapid corrosion rate under physiological conditions has limited the actual clinical application. This study reports the use of a novel biomimetic polyelectrolyte multilayer template, based on polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) via layer-by-layer (LbL) assembly, to improve the corrosion resistance of the alloy. Surface characterization techniques (field-emission scanning electron microscopy, Fourier transform infrared (FTIR) spectrophotometer and X-ray diffractometer) confirmed the formation of biomineralized Ca-P coating on AZ31 alloy. Both hydrogen evolution and electrochemical corrosion tests demonstrated that the corrosion protection of the polyelectrolyte-induced Ca-P coating on AZ31 alloy. The formation mechanism of biomineralized Ca-P coating was proposed.

Order and disorder in (E)-[1-(biphenyl-4-yl)ethylidene]hydrazine: a structural, spectroscopic and theoretical study.

An unexpected global disorder (co-existing rotational disorder and glide disorder) has been observed during an X-ray investigation of the crystal structure of (E)-[1-(biphenyl-4-yl)ethylidene]hydrazine, C14H14N2, at room temperature. When the temperature decreases to 273 K, the disorder disappears, but the quality of the data set is low. The diffraction data were collected again at 110 K. Differential scanning calorimetry (DSC) analysis and polarizing-microscopy experiments, as well as a fourth set of single-crystal data collected at 283 K, proved that the order-disorder transformation occurs continuously. The analyses of these crystal structures and full-range relaxed potential energy surface scans showed that this kind of global disorder is not very difficult to achieve inside the crystal. Experimental and theoretical studies via UV-Vis and fluorescence spectra impart an understanding on the prediction methods of optical properties, which are essential for the rational design of biphenyl-based materials with pre-defined properties.

Unusual Flexibility of Microporous Sulfides during Ion Exchange.

Open-framework chalcogenides with ion-exchange capacity are promising materials for removing hazardous heavy-metal ions and for capturing radioactive Cs+. However, research on the exchange mechanism is limited, especially for the framework chalcogenides that have multiple bridging anions. Generally, open-framework chalcogenides that have multiple bridging anions at the window or wall of the channels are rigid during the ion-exchange process. We show here that microporous sulfides with µ3-S2- (where µ3 = triple bridging mode) at the windows exhibit framework flexibility upon ion exchange. Three new microporous sulfides Na4Cu8Ge3S12·2H2O (1), Na3(Hen)Cu8Sn3S12 (where en = ethylenediamine) (2) and (dap)2(Hdap)4Cu8Ge3S18 (where dap = 1,2-diaminopropane) (3) were synthesized under solvothermal conditions. Compounds 1 and 2 contain a copper-rich framework composed of icosahedral [Cu8S12]16- units linked via monomeric GeS44- or SnS44- tetrahedral units, whereas compound 3 features an expanded framework composed of icosahedral [Cu8S12]16- units interconnected with dimeric Ge2S64- units. These compounds exhibit unusual ion-exchange properties. Specifically, the frameworks of 1 and 2 (with µ3-S at the small windows) show "breathing action" upon ion exchange of K+ or Rb+, which have relative large sizes, and compound 3 exhibits framework flexibility upon Cs+ ion exchange with both space group and channels changed.

A new hybrid anchoring balloon for direct peroral cholangioscopy using an ultraslim upper endoscope.

BACKGROUND AND AIM: Large impacted or residual invisible common bile duct (CBD) stones after mechanical lithotripsy are challenging. We aimed to evaluate the feasibility and success rate of a new hybrid anchoring balloon-guided direct peroral cholangioscopy (POC) for these conditions using an ultraslim endoscope. METHODS: Sixty-five patients with large or residual invisible CBD stones for direct POC from July 2012 to July 2016 were identified, including six cases in whom an additional interventional procedure was required. There were altogether 55 cases undergoing a procedure with our new device, with a 0.021-inch guidewire tied to a balloon catheter at its distal end in this single-center retrospective study. Technical success, procedure time, diagnostic and therapeutic efficacy of direct POC, and procedure-related complications were studied. RESULTS: The hybrid anchoring balloon-guided direct POC was successful in 51/55 (92.7%) procedures, including 18 cases in whom the conventional wire-guided method failed within 25 min. Mean time for technical success by our method was 12.4 ± 3.4 min. In total, of the 43 cases with previous removal of CBD stones, seven (16.3%) were found to have residual stones ≥4 mm, excluding three cases in whom direct POC failed. In another 25 cases for difficult stones, 24 lithotripsies were carried out, resulting in 23 complete fragmentations. No significant procedure-related complications were observed. CONCLUSION: The new hybrid anchoring balloon device performs well in facilitating direct POC using an ultraslim endoscope for evaluation and extraction of residual or large impacted CBD stones.

Syntheses and Characterization of Chiral Zeolitic Silver Halides Based on 3-Rings.

The synthesis of chiral zeolites remains a significant challenge because the primary tetrahedral building units are achiral and weak interactions exist between the guest and host frameworks. Here, we present the syntheses and characterization of three new chiral zeolitic halides, [H3(Dabco)2]Ag3X6 (X = Br (1) or I (2), Dabco = 1,4-diazabicyclo[2.2.2]octane) and [H2(Dabco)][(Dabco)Ag4I6] (3). Compounds 1 and 2 are isostructural, containing a 4-connected zeolitic framework built up from 3-ring units, with high-charge [H3(Dabco)2]3+ located in chiral cages. Compound 3 contains a similar zeolitic [Ag3I6]3- framework to that of 2, but a [Ag(Dabco)]+ unit is incorporated in each 3-ring, with [H2(Dabco)]2+ located in channels. These frameworks are chiral, representing the first examples of chiral zeolitic halides. The chirality transference of the frameworks for 1 and 2 was attributed to the template effect of the chiral [H3(Dabco)2]3+ through strong electrostatic interactions and multiple hydrogen-bond interactions. For compound 3, direct coordination interactions play important roles in the chirality transference from the chiral Dabco ligand to the framework.

Coordination-Induced Syntheses of Two Hybrid Framework Iodides: A Thermochromic Luminescent Thermometer.

Two new 3D hybrid framework iodides, Hmta[(Hmta)Ag4I4] (1; Hmta = hexamethylenetetramine) and [(Hmta)2Ag8I6]I2 (2), have been synthesized under solvothermal conditions. Compound 1 consists of a neutral 3D framework built up from alternation of the tetrahedral Ag4I4 unit and Hmta with dia-b topology. Compound 2 features a 3D cationic framework with flu topology, constructed by cationic [Ag8I6](2+) units linked with Hmta. Tetrahedral Hmta plays crucial structure-directing roles in the formation of these 3D frameworks with high symmetry. The temperature-dependent photoluminescent measurement reveals luminescent thermochromism of the compounds, the emission maximum of which shows a gradual blue shift with increasing temperature. The results indicate that 1 is a promising wavelength- and intensity-dependent luminescent thermometer applicable in two different temperature ranges.

Perfusion of gastrodin in abdominal aorta for alleviating spinal cord ischemia reperfusion injury.

OBJECTIVE: To observe the effects of perfusion of the gastrodin in abdominal aorta for alleviating the spinal cord ischemia reperfusion injury (SCIRI). METHODS: A total of 36 New Zealand white rabbits were divided randomly into sham-operated group (group S), control group (group C) and gastrodin group (group G), 12 rabbits for each group. Aorta abdominalis infrarenalis blocking method was applied to establish the SCIRI model. The changes of motor evoked potentials (MEPs) before the ischemia and on 30 min, 60 min, 6 h, 12 h and 24 h of reperfusion of the gastrodin were respectively recorded, and the neurologic function score before the ischemia, on the 6 h, 12 h and 24 h of the reperfusion of the gastrodin were assessed. And the changes of the concentration of serum neuron specific enolase (NSE), interleukin (IL)-lß and IL-8 were measured before the ischemia, after 45 min of ischemia, and on 30 min, 60 min, 6 h, 12 h and 24 h of reperfusion of gastrodin. Then the levels of spinal cord nerve cells mitochondrial superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), total antioxidant capacity (T-AOC) and mitochondrial swelling degree (MSD) were tested and the histopathologic changes in spinal cord tissues were observed. RESULTS: The levels of the NSE, IL-lß, IL-8, ROS, MDA and MSD of group C were all significantly elevated after the ischemia (P < 0.01); the levels of the spinal nerve cell mitochondria SOD, GSH-PX and T-AOC were all significantly reduced (P < 0.01), MEPs and spinal cord tissue pathology were damaged significantly (P < 0.01). The rate of motor neuron abnormalities and the damages of spinal cord tissue pathology of group G were significantly milder than those of group C (P < 0.01); the levels of NSE, IL-lß, IL-8, ROS, MDA and MSD were significantly lower than those of group C (P < 0.01), but the levels of SOD, GSH-PX and T-AOC were all significantly higher than those of group C (P < 0.01), and the recovery of neurologic function score during the reperfusion of gastrodin was significantly faster than group C (P < 0.01). CONCLUSIONS: Perfusion of the gastrodin in abdominal aorta can alleviate the spinal cord ischemia reperfusion injury by promoting the mitochondrial antioxidant capacity and inhibiting the inflammatory reaction.

Domain Motions and Functionally-Key Residues of L-Alanine Dehydrogenase Revealed by an Elastic Network Model.

Mycobacterium tuberculosis L-alanine dehydrogenase (L-MtAlaDH) plays an important role in catalyzing L-alanine to ammonia and pyruvate, which has been considered to be a potential target for tuberculosis treatment. In the present work, the functional domain motions encoded in the structure of L-MtAlaDH were investigated by using the Gaussian network model (GNM) and the anisotropy network model (ANM). The slowest modes for the open-apo and closed-holo structures of the enzyme show that the domain motions have a common hinge axis centered in residues Met133 and Met301. Accompanying the conformational transition, both the 1,4-dihydronicotinamide adenine dinucleotide (NAD)-binding domain (NBD) and the substrate-binding domain (SBD) move in a highly coupled way. The first three slowest modes of ANM exhibit the open-closed, rotation and twist motions of L-MtAlaDH, respectively. The calculation of the fast modes reveals the residues responsible for the stability of the protein, and some of them are involved in the interaction with the ligand. Then, the functionally-important residues relevant to the binding of the ligand were identified by using a thermodynamic method. Our computational results are consistent with the experimental data, which will help us to understand the physical mechanism for the function of L-MtAlaDH.

Study, by use of coarse-grained models, of the functionally crucial residues and allosteric pathway of anesthetic regulation of the Gloeobacter violaceus ligand-gated ion channel.

Although pentameric ligand-gated ion channels (pLGICs) have been found to be the targets of general anesthetics, the mechanism of the effects of anesthetics on pLGICs remains elusive. pLGICs from Gloeobacter violaceus (GLIC) can be inhibited by the anesthetic ketamine. X-ray crystallography has shown that the ketamine binding site is distant from the channel gate of the GLIC. It is still not clear how ketamine controls the function of the GLIC by long-range allosteric regulation. In this work, the functionally crucial residues and allosteric pathway of anesthetic regulation of the GLIC were identified by use of a coarse-grained thermodynamic method developed by our group. In our method, the functionally crucial sites were identified as the residues thermodynamically coupled with binding of ketamine. The results from calculation were highly consistent with experimental data. Our study aids understanding of the mechanism of the anesthetic action of ketamine on the GLIC by long-range allosteric modulation.

[Characteristics of hydroxyapatite/PMMA nanocomposites for provisional restoration and its biocompatibility with human gingival fibroblasts].

OBJECTIVE: To formulate hydroxyapatite (HA)/polymethyl methacrylate (PMMA) composites with improved cytocompatibility for provisional restoration. METHODS: Nanocomposites with 20 wt%, 30 wt%, 40 wt%, and 50 wt% HA/PMMA (H/P) were developed and examined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Human gingival fibroblasts were cultured on those HA/PMMA discs and investigated by fluorescent staining on 24 h and MTT assay at 1 d, 3 d, 5 d and 7 d. RESULTS: Chemical integration of HA/PMMA interface was confirmed by XPS. Typical fusiform cells with adhesion spots were detected on 40 wt% and 50 wt% H/P discs. MTT results showed insignificant differences in cell growth between 40 wt% H/P and pure titanium (Ti, P > 0.05), while the other H/P discs showed significantly lower cell growth than pure Ti (P < 0.05). CONCLUSION: 40 wt% H/P might be a promising candidate for provisional dental implant restoration and for esthetic gingival contour.

4-Nitro-N2

In the title compound, C12H10N4O2, the dihedral angle between the aromatic rings is 43.18 (16)°. The nitro group is rotated from its attached ring by 7.8 (2)° and a short intra-molecular N-H⋯N contact occurs. In the crystal, the mol-ecules are linked by N-H⋯N and C-H⋯O hydrogen bonds, generating a three-dimensional network.

Hierarchical MnO2/SnO2 heterostructures for a novel free-standing ternary thermite membrane.

We report the synthesis of a novel hierarchical MnO2/SnO2 heterostructures via a hydrothermal method. Secondary SnO2 nanostructure grows epitaxially on the surface of MnO2 backbones without any surfactant, which relies on the minimization of surface energy and interfacial lattice mismatch. Detailed investigations reveal that the cover density and morphology of the SnO2 nanostructure can be tailored by changing the experimental parameter. Moreover, we demonstrate a bottom-up method to produce energetic nanocomposites by assembling nanoaluminum (n-Al) and MnO2/SnO2 hierarchical nanostructures into a free-standing MnO2/SnO2/n-Al ternary thermite membrane. This assembled approach can significantly reduce diffusion distances and increase their intimacy between the components. Different thermite mixtures were investigated to evaluate the corresponding activation energies using DSC techniques. The energy performance of the ternary thermite membrane can be manipulated through different components of the MnO2/SnO2 heterostructures. Overall, our work may open a new route for new energetic materials.

4-Meth-oxy-3-(meth-oxy-meth-yl)benzalde-hyde.

In the title compound, C10H12O3, the dihedral angle between the benzene ring and the meth-oxy-methyl side chain is 9.7 (2)°. The O atom of the aldehyde group and the C atom of the meth-oxy group deviate from the plane of the ring by 0.039 (3) and 0.338 (4) Å, respectively. The only inter-molecular inter-actions are very weak C-H⋯π inter-actions.

[Study of Dioscorea opposita Thunb from different producing areas with XRF and PXRD].

The contents of various elements in rhizoma dioscoreae were analyzed and compared with those of shishou D. opposita Thunb on the whole jointly by XRF and PXRD. The results showed that the element Cu, Al and Mn could not be detected in rhizoma dioscoreae, but the element Mg, Zn and Cr were found, and other elements contents changed to different degrees; there are starch and whewellite in both groups, the crystal type of starches separated from rhizoma dioscoreae cultivars was a typical B-type pattern, but as C-type and V-type in shishou D. opposita Thunb, which is a mixture of A-type, B-type and V-type. The combination of two testing techniques could be applied to the mensuration and analysis of the elements and micro-structural of Dioscorea opposita Thunb which could be from different producing areas.

Shear bond strengths between alumina-toughened zirconia cores and veneering ceramics and their susceptibility to aging.

OBJECTIVE: To evaluate the shear bond strength (SBS) between alumina-toughened zirconia (ATZ) cores and veneering ceramics, investigate the effect of aging in artificial saliva on SBS and compare it with that of yttria-stabilized tetragonal zirconia polycrystals(Y-TZP). METHODS: Bars of ATZ and Y-TZP were layered with veneering ceramics in accordance to the recommendation of the manufacturer. Half of each group (n = 10) was aged at 134 °C (under 2 bar pressure) in an autoclave for 48 h. Subsequently, all specimens were subjected to shear force in a universal testing machine. The interface and fractured surface of the specimens were evaluated using scanning electron microscopy and X-ray energy dispersive spectroscopy. RESULTS: The initial mean SBS values in MPa±SD were 28.9±8.0 for ATZ and 26.2±7.6 for Y-TZP. After aging, the mean SBS values for ATZ and Y-TZP were 22.9±4.9 MPa and 22.8±6.9 MPa, respectively. Neither the differences between the SBS values of the ATZ and Y-TZP groups nor the influence of aging on all groups were statistically significant. CONCLUSIONS: The SBS between the ATZ core and the veneering ceramics was not affected by aging. The SBS of ATZ to veneering ceramics was not significantly different compared with that of Y-TZP.

[Evaluation of alumina effects on the mechanical property and translucency of nano-zirconia all-ceramics].

OBJECTIVE: To study the effects of alumina content on sintered density, mechanical property and translucency of zirconia nanocomposite all-ceramics. METHODS: Specimens of zirconia nanocomposite all-ceramics were divided into five groups based on their alumina content which are 0% (control group), 2.5%, 5.0%, 7.5% and 10.0% respectively. The sintered densities were measured using Archimedes' method. Specimens' bending strengths were measured with three-point bending test (ISO 6872). The visible light transmittances were measured with spectrophotometric arrangements and the fractured surfaces were observed using scanning electron microscope (SEM). RESULTS: The control group of pure zirconia could be sintered to the theoretical density under pressure-less sintering condition. The bending strength was (1100.27 ± 54.82) MPa, the fracture toughness was (4.96 ± 0.35) MPa×m(1/2) and the transmittance could reach 17.03%. The sintered density and transmittance decreased as alumina content increased from 2.5% to 10%. However, the fracture toughness only increased slightly. In all four alumina groups, the additions of alumina had no significant effect on samples' bending strengths (P > 0.05). When the content of alumina was 10%, fracture toughness of specimens reached (6.13 ± 0.44) MPa×m(1/2) while samples' transmittance declined to 6.21%. SEM results showed that alumina particles had no significant effect on the grain size and distribution of tetragonal zirconia polycrystals. CONCLUSIONS: Additions of alumina to yttria-tetragonal zirconia polycrystals could influence its mechanical property and translucency. Additions of the other phase to zirconia ceramics should meet the clinical demands of strength and esthetics.