Simple Suction Research Articles

Stereospecific supramolecular polymerization of nanoclusters into ultra-long helical chains and enantiomer separation

During the construction of supramolecular polymers of smaller nanoparticles/nanoclusters bearing hierarchy and homochirality, the mechanism understanding via intuitive visualization and precise cross-scale chirality modulation is still challenging. For this goal, a cooperative self-assembly strategy is here proposed by using ionic complexes with uniform chemical composition comprising polyanionic nanocluster cores and surrounded chiral cationic organic components as monomers for supramolecular polymerization. The single helical polymer chains bearing a core-shell structure at utmost length over 20 μm are demonstrated showing comparable flexibility resembling covalent polymers. A nucleation-elongation growth mechanism that is not dealt with in nanoparticle systems is confirmed to be accompanied by strict chiral self-sorting. A permeable membrane prepared by simple suction of such supramolecular polymers displays high enantioselectivity (e.e. 98% after four runs) for separating histidine derivatives, which discloses a benefiting helical chain structure-induced functionalization for macroscopic supramolecular materials in highly efficient racemate separation.

High-performance lithium metal anode enhanced by multifunctional film of PAN@AgNWs with antimicrobial activity

Lithium metal is expected to be the perfect anode material for the next generation of rechargeable batteries owing to its ultra-high theoretical specific capacity, low density and the lowest redox potential. However, the practical application of lithium metal batteries faces serious challenges, including uneven lithium deposition, negative electrode volume expansion, and short circuits brought by dendritic protrusions. Although the 3D structure of silver nanowires is effective in inhibiting lithium dendrite growth and lithium metal volume expansion, it still suffers from lithium inhomogeneity caused by uneven distribution of silver nanowires and complicated preparation. Therefore, PAN@AgNWs collector was prepared by a simple suction filtration method, and uniform dispersion of silver nanowires and uniform deposition of lithium were achieved. Lithium nucleation overpotential and lithium dendrite formation can be effectively reduced by PAN@AgNWs hosts due to the reduction of local current density by 3D collectors and the improved lithiophilicity of silver nanowires. With low voltage hysteresis, the symmetric battery constructed with its composite anode may cycle steadily for 4500 h at 1 mA cm−2 and 1 mAh cm−2. At the same time, the Li-PAN@AgNWs||LFP full cell still possesses a reversible of 144.18 mAh g−1 after 500 cycles at 1C. Moreover, due to large specific surface area and high surface energy of 3D silver nanowires, it exhibits excellent antimicrobial properties, with an inactivation efficiency of 96.3 % after contacting with E. coli for 2.5 h. This work shows the possibility of using PAN@AgNWs in a large scale for LMBs, and paves the way for development of high-performance antimicrobial materials.

Outcomes of Endoscopic Intervention Using Over-the-Scope Clips for Anastomotic Leakage Involving Secondary Fistula after Gastrointestinal Surgery: A Japanese Multicenter Case Series.

The over-the-scope clip (OTSC) is a highly effective clipping device for refractory gastrointestinal disease. However, Japanese data from multicenter studies for anastomotic leakage (AL) involving a secondary fistula after gastrointestinal surgery are lacking. Therefore, this study evaluated the efficacy and safety of OTSC placement in Japanese patients with such conditions. We retrospectively collected data from 28 consecutive patients from five institutions who underwent OTSC-mediated closure for AL between July 2017 and July 2020. The AL and fistula were located in the esophagus (3.6%, n = 1), stomach (10.7%, n = 3), small intestine (7.1%, n = 2), colon (25.0%, n = 7), and rectum (53.6%, n = 15). The technical success, clinical success, and complication rates were 92.9% (26/28), 71.4% (20/28), and 0% (0/28), respectively. An age of <65 years (85.7%), small intestinal AL (100%) and colonic AL (100%), defect size of <10 mm (82.4%), time to OTSC placement > 7 days (84.2%), and the use of simple suction (78.9%) and anchor forceps (80.0%) were associated with higher clinical success rates. OTSC placement is a useful therapeutic option for AL after gastrointestinal surgery.

A bacterial cellulose-based separator with tunable pore size for lithium-ion batteries

Bacterial cellulose (BC) lithium-ion batteries separators possess outstanding thermal dimensional stability and electrolyte wettability, but theirs nano diameter and high aspect ratio lead to poor porosity and pore size uniformity of dense BC separators, limiting the Li+ transmission in the separators. In this paper, chitosan (CS) with different molecular weight was grafted onto BC (named OBCS), and a high-performance OBCS separator with excellent pore structure and tunable pore size was prepared by simple suction filtration. The spacing and dispersion uniformity of OBCS were improved by the CS grafted on BC surface, thus improving the pore structure and porosity of OBCS separators. The results showed that the obtained OBCS separators not only have excellent physicochemical properties, but also exhibit higher electrochemical performances than the commercial polypropylene (PP) separator. This work provides a new feasible strategy for improving the pore structure and porosity of nanocellulose separators.

Continuous graphene oxide nanolayer arranged on hydrophilic modified polytetrafluoroethylene substrate to construct high performance proton exchange membranes

Graphene oxide (GO) nanolayer, combining extraordinary mechanical properties, separation performance and chemical stability, holds great promise for widespread applications. The current preparation of GO nanolayer is complex and requires expensive and technical equipment, which limits the further development. In this work, we deposit GO nanolayer on TiO2 modified Polytetrafluoroethylene (PTFE) film by controlling the concentration of GO in suction filtration process. Subsequently, Nafion is sprayed on the surface of the complex to construct a composite membrane with excellent proton conductivity and prominent fuel isolation efficiency (methanol permeability: 4.18 × 10−7 cm2 s−1; hydrogen permeability: 2.76 × 10−15 mol m−1 s−1 Pa−1). Compared with commercial Nafion 117, the TiO2 modified PTFE/GO film acts as the substrate to reduce the content of Nafion (reduced by 70%). Through simple suction filtration process, the high-performance fuel cell composite membrane can be prepared with low-cost, which greatly promotes the application process of fuel cell.

Efficiency and usability of an elementary hand-held suction assembly in paediatric tracheostomised patients.

Commercially available suction devices are expensive, large and heavy, and need electricity, and thus restrict the outdoor activity of tracheostomised children and their carers. This study evaluated the efficacy and usability of a simple suction assembly using a syringe and feeding tube in paediatric tracheostomised patients. Following the domiciliary usage of this suction assembly instead of their existing suction device for a minimum of 15 days, carers responded to a set of questionnaires containing a subjective scoring system. Ninety-three per cent of the carers considered this assembly as average, good or very good in cleaning the tracheostomy tube. Eighty per cent of the carers considered that this assembly would be suitable when their existing suction machines are unavailable, indicating high usability, and 66.67 per cent of the carers would be confident using this assembly in outdoor settings. Larger studies with objective evaluation methods can validate the high efficacy of this simple, inexpensive and easy-to-use, hand-held suction apparatus as reported by the carers of 15 paediatric tracheostomised patients in this study.

A poly(amidoxime)-modified MOF macroporous membrane for high-efficient uranium extraction from seawater

Abstract Although metal–organic frameworks (MOFs) own excellent uranium adsorption capacity but are still difficult to conveniently extract uranium from seawater due to the discrete powder state. In this study, a new MOF-based macroporous membrane has been explored, which can high-efficiently extract uranium through continuously filtering seawater. Through modifying the UiO-66 with poly(amidoxime) (PAO), it can disperse well in a N,N-dimethylformamide solution of graphene oxide and cotton fibers. Then, the as-prepared super-hydrophilic MOF-based macroporous membrane can be fabricated after simple suction filtration. Compared with nonmodified MOFs, this UiO-66@PAO can be dispersed uniformly in the membrane because it can stabilize well in the solution, which have largely enhanced uranium adsorbing capacity owing to the modified PAO. Last but not least, different from powder MOFs, this UiO-66@PAO membrane provides the convenient and continuously uranium adsorbing process. As a consequence, the uranium extraction capacity of this membrane can reach 579 mg·g−1 in 32 ppm U-added simulated seawater for only 24 h. Most importantly, this UiO-66@PAO membrane (100 mg) can remove 80.6% uranyl ions from 5 L seawater after 50 filtering cycles. This study provides a universal method to design and fabricate a new MOF-based adsorbent for high-efficient uranium recovery from seawater.

Hand-powered vacuum-driven microfluidic gradient generator for high-throughput antimicrobial susceptibility testing

The growth of bacterial resistance to antimicrobials is a serious problem attracting much attention nowadays. To prevent the misuse and abuse of antimicrobials, it is important to carry out antibiotic susceptibility testing (AST) before clinical use. However, conventional AST methods are relatively laborious and time-consuming (18–24 h). Here, we present a hand-powered vacuum-driven microfluidic (HVM) device, in which a syringe is used as the only vacuum source for rapid generating concentration gradient of antibiotics in different chambers. The HVM device can be preassembled with various amounts of antibiotics, lyophilized, and stored for ready-to-use. Bacterial samples can be loaded into the HVM device through a simple suction step. With the assistance of Alamar Blue, the AST assay and the minimum inhibitory concentration (MIC) of different antibiotics can be investigated by comparing the growth results of bacteria in different culture chambers. In addition, a parallel HVM device was proposed, in which eight AST assays can be performed simultaneously. The results of MIC of three commonly used antibiotics against E. coli K-12 in our HVM device were consistent with those obtained by traditional method while the detection time was shortened to less than 8 h. We believe that our platform is high-throughput, cost-efficient, easy to use, and suitable for POCT applications.

Clinical Presentation, Management and Outcome of Gestational Trophoblastic Diseases Admitted in Chittagong Medical College Hospital

Background: Gestational Trophoblastic Disease (GTD) is a heterogeneous group of diseases that includes partial and complete hydatidiform mole, invasive mole, choriocarcinoma and placental site trophoblastic tumour. The study aimed to determine the clinical presentation management options and outcome of GTD in patients admitted in a tertiary hospital of Bangladesh.&#x0D; Materials and methods: This prospective observational study included 50 patients with GTD from the Obstetrics and Gynaecology Department of Chittagong Medical College Hospital, during the period of July 2013 to December 2013. The demographic profile, clinical presentation, management, outcome and complications were studied.&#x0D; Results: Mean age was 25.40 ± 8.34 years with most of the patients (46%) were in age group 20 - 29 years. 42% participants were primigravida. The commonest symptom after bleeding per-vaginum (94%) was amenorrhea (90%). Maximum cases (80%) were of complete hydatidiform mole. Rate of progression to invasive mole and choriocarcinoma were found 6% and 10% respectively. Suction evacuation and hysterectomy were the treatment option. One patient (2%) expired due to excessive bleeding.&#x0D; Conclusion: The majority of cases are cured by simple suction uterine curettage. Regular follow up is important to estimate the true incidence of this disease.&#x0D; JCMCTA 2021 ; 32 (2) : 128-131

Gold(I)-Catalyzed Oxidative Amination of β-Amino-ynones to Quaternary Ammonium-olate Salts: The Benefit of a P,N-Bidentate Ligand.

A novel P,N-bidentate ligand-assisted gold-catalyzed oxidative amination of β-amino-ynones has been developed, allowing the simple and efficient construction of various quaternary ammonium-olate salts in good to excellent yields. These unprecedented quaternary ammonium-olate salts can be isolated and purified via simple suction filtration. The broad substrate scope, easy purification, easy further transformation, and mild conditions make it a viable alternative for the synthesis of various quaternary ammonium-olate salts.

Highly thermally conductive epoxy composites with anti-friction performance achieved by carbon nanofibers assisted graphene nanoplatelets assembly

Thermally conductive epoxy composites have a broad range of applications in many fields relating to microelectronic devices and encapsulating materials of high-power electrical appliance. However, it is still a challenge to effectively fabricate thermally conductive epoxy composite materials that have various excellent comprehensive properties. In this work, a simple suction filtration method is developed to construct the self-supported framework of graphene nanoplatelets (GNPs) and carbon nanofibers (CNFs), and then epoxy is impregnated into the framework to prepare the composites. The morphological characterizations show that one dimensional CNFs exhibit the “supporting” effect between the parallelly arranged GNP layers in axial direction and the “bridging” effect between adjacent GNP aggregates in radial direction, and the self-supported framework is maintained in the epoxy composites. The highest thermal conductivities are 3.74 W/m·K in radial direction and 3.28 W/m·K in axial direction, at filler contents of 13.09 and 14.49 wt%, respectively, which are 1770% and 1540% higher than that of the pure epoxy. Further results show that the composite samples have high storage modulus, enhanced thermal resistance, and improved anti-friction performance, all of them ensure that the epoxy composites can be used as the materials of the components and parts of the electrical appliance toward continuous loading, vibration, and large heat dissipation.

Switchable Microvalves Employing a Conducting Polymer and Their Automatic Operation in Conjunction with Micropumps with a Superabsorbent Polymer.

Automated microfluidic devices integrated with microvalves and micropumps were developed. To realize an efficient and automatic control of solution transport, we newly developed microvalves comprising a polypyrrole (PPy) film electropolymerized on patterned platinum electrodes and doped with a surfactant. The surface of the doped PPy film exhibits a nearly hydrophobic state or a hydrophilic state when oxidized or reduced under the application of an appropriate potential, enabling the control of the solution transport via capillary action. The simple structure and fabrication of the microvalves facilitated the integration of many valves in various flow channel structures. To improve the performance, simple suction and injection micropumps with freeze-dried discs made of a superabsorbent polymer (SAP) were additionally incorporated along with the microvalves. The former withdraws the solution by directly absorbing it onto the SAP, whereas the latter applies a pressure to the solution through an elastic diaphragm by absorbing a priming solution into the SAP. The significant volume changes of the SAP discs enabled an efficient transport of the solutions. Repeated injection and withdrawal of the solutions in and out of a reaction chamber were demonstrated using four injection and suction pumps and eight valves.

Wrinkled Flower‐Like Reduced Graphene Oxide for High‐Performance Supercapacitors

AbstractThe preparation of reduced graphene oxide (rGO) by an oxidation‐reduction chemical reaction is very extensive. However, during the oxidation process, the obtained graphene oxide (GO) is usually not uniform in size and contains some incompletely oxidized graphite particles. To obtain uniformly small‐sized GO and remove impurities, we put forward here a simple suction filtration process, that is, when GO passes through the filter, it is preferentially selected. In this way, we provide a facile but effective method for the screening of GO and then obtain wrinkled flower‐like rGO (WF rGO) with excellent electrochemical performance. We also perform a design of experiments to optimize the reduction procedure. It is found that such factors as the reaction time, temperature, reductant and KOH content all affect the microstructure and electrochemical properties of rGO. With the optimized reduction procedure used, the specific capacitance of rGO can reach 231 F/g at the current density of 0.5 A/g. Furthermore, through the suction filtration along with the optimization of reduction, the WF rGO shows a much higher specific capacitance of 272 F/g. On this basis, the energy density of a symmetric rGO//rGO capacitor device arrives at 10.9 Wh/kg at a power density of 0.5 kW/kg and 8.2 Wh/kg at 12.6 kW/kg, and the capacitance keeps 91.5 % after 10,000 cycles. Moreover, the WF rGO//WF rGO device possesses a significantly higher energy density of 12.1 Wh/kg at a power density of 0.5 kW/kg and 9.7 Wh/kg at 24.2 kW/kg, and the capacity perfectly remains 94 % of its initial value after 10,000 cycles.

Two-Dimensional Supramolecular Ionic Frameworks for Precise Membrane Separation of Small Nanoparticles

Supramolecular frameworks driven by intermolecular interactions represent a new type of porous materials differing from those driven by covalent or coordination bonding. The intermolecular interaction-induced flexible assembly structures display unique advantages in materials processing, structure stimuli-responses and recyclings. In this work, a two-dimensional (2D) supramolecular-ionic framework (SIF) was constructed through the initial ionic interaction between host cation and polyoxometalate polyanion and then the host-guest inclusion of the formed host ionic complex with a four-arm porphyrin guest molecule following a 2+4 reaction. Several prepared framework monolayer bearing orthometric grid structure constituted a nanosheet-like assembly with flexibility and exhibited processability, which provided the feasibility for further preparation of separation membrane via a simple suction procedure of their dispersed suspensions in mixed solvents. The nano-filtration based on the uniform square pores under a slightly reduced pressure successfully achieved a precise separation of several types of nanoparicles and molecular clusters in wide distribution at a cutting off value as small as 2.2 nm. These results also implied potentials of the present strategy for more separations at molecluar level and very fine nanoscale.

Comparison and evaluation of three techniques for treating auricular pseudocyst

Background Auricular pseudocyst is a benign cystic lesion in cartilages of the auricle. Different methods are currently used to manage this disease. In these methods, simple aspiration combined with pressure dressing, local steroid injection and surgery are the most prevalent therapies. Objective To find the best clinical path for the treatment of auricular pseudocyst. Methods Eighty-four subjects were randomly allocated into three equal groups (Group A: simple suction combined with pressure dressing; Group B: suction and local steroid injection; and, Group C: surgery). Two otolaryngologists assessed effective rate, sequelae and degree of satisfaction at three-month follow-up. A visual analog scale was used to determine degree of satisfaction. Results Group A had the lowest effective rate (54%). Group C was highest in terms of effectiveness (100%) but also in incidence of sequelae (71%). Group B had a slightly lower effective rate (86%) than Group C, but the incidence of sequelae was lowest (42%). Degree of satisfaction was highest (7.0 ± 2.7) for Group B. Conclusion Local steroid injection should be the first choice for the treatment of auricular pseudocyst because of high satisfaction, favorable effectiveness and few sequelae. Where this method is ineffective, surgery should be used.

An easy way to make blisters in suction blister grafting of vitiligo with Hijama therapy cups

Suction blister grafting is a well-known surgical treatment for stable vitiligo. 1 Khunger N. Kathuria S.D. Ramesh V. Tissue grafts in vitiligo surgery—past, present, and future. Indian J Dermatol. 2009; 54: 150-158 Crossref PubMed Scopus (48) Google Scholar Making blisters of adequate size is of utmost importance for the success of the technique. Unavailability of a suction machine makes this technique difficult to perform. 2 Burm J.S. Simple suction device for autologous epidermal grafting. Plast Reconstr Surg. 2000; 106: 1225-1226 Crossref PubMed Scopus (11) Google Scholar

Safety and efficacy of a simple cardiotomy suction system as a blood salvage procedure during off-pump coronary artery bypass surgery.

The ideal blood-salvaging strategies for off-pump coronary artery bypass graft procedures have not been determined. We developed a new blood-salvaging system that uses a cardiotomy suction. The purpose of this study was to examine the efficacy of this novel method. This was a retrospective study involving 50 consecutive patients undergoing off-pump coronary artery bypass grafting. In 25 patients, a simple cardiotomy suction system was used (cardiotomy suction group). These individuals were compared with 25 historical cohorts who were treating with the conventional cell saver system (cell saver group). There was no in-hospital mortality in either group. In the cell saver group, there was one major complication (stroke) and two minor complications (saphenous vein graft occlusion, superficial wound infection). In the cardiotomy suction group, there was one minor complication (subclinical pulmonary emboli). The cardiotomy suction group received significantly fewer transfused RBC (cardiotomy: 0.56 ± 1.4 units vs. cell saver: 2.46 ± 3.3 units, p = 0.005). The serum total protein and albumin levels were significantly higher in the cardiotomy group. Our newly developed simple cardiotomy suction system, when compared with the conventional cell saver system, produced similar clinical results and attenuated postoperative hemodilution. Our system may emerge as a preferable alternative for blood salvage during off-pump coronary artery bypass grafting.

Near-infrared emissive lanthanide hybridized nanofibrillated cellulose nanopaper as ultraviolet filter

The lanthanide complexes [Yb(fac)3(H2O)2, Yb(tta)3(H2O)2, Nd(tta)3(H2O)2] functionalized nanofibrillated cellulose (Ln-NFC) nanopapers with near-infrared (NIR) luminescence and high transparency are rapidly fabricated after solvent exchange using a simple suction filtration film-making method. The effects of NFC and lanthanide complexes content on their photophysical properties of Ln-NFC nanopapers and their mechanism of UV filters are fully investigated. With increasing lanthanide complexes content in the Ln-NFC nanopaper, their transmittances are gradually decreased while their NIR luminescences are obviously increased. Yb-fac NFC nanopaper has high UVB block rate at 298 nm, whereas the high UVA block ratio of Ln-tta NFC nanopaper is observed at 345 nm. Ln-NFC nanopapers show a much higher photostability without decomposition under UV irradiation at 365 nm over 5 h. The emission spectra of the Ln-NFC nanopaper process the NIR luminescence of the corresponding lanthanide ions through the efficient triplet–triplet energy transfer process. Ln-NFC nanopapers can bring a brilliant future for UV filters, labeling fields and marking soft materials application.

Enhanced aerodynamic reach of vapor and aerosol sampling for real-time mass spectrometric detection using Venturi-assisted entrainment and ionization

Venturi-assisted ENTrainment and Ionization (VENTI) was developed, demonstrating efficient entrainment, collection, and transport of remotely sampled vapors, aerosols, and dust particulate for real-time mass spectrometry (MS) detection. Integrating the Venturi and Coandă effects at multiple locations generated flow and analyte transport from non-proximate locations and more importantly enhanced the aerodynamic reach at the point of collection. Transport through remote sampling probes up to 2.5 m in length was achieved with residence times on the order of 10−2 s to 10−1 s and Reynolds numbers on the order of 103 to 104. The Venturi-assisted entrainment successfully enhanced vapor collection and detection by greater than an order of magnitude at 20 cm stand-off (limit of simple suction). This enhancement is imperative, as simple suction restricts sampling to the immediate vicinity, requiring close proximity to the vapor source. In addition, the overall aerodynamic reach distance was increased by approximately 3-fold over simple suction under the investigated conditions. Enhanced aerodynamic reach was corroborated and observed with laser-light sheet flow visualization and schlieren imaging. Coupled with atmospheric pressure chemical ionization (APCI), the detection of a range of volatile chemical vapors; explosive vapors; explosive, narcotic, and mustard gas surrogate (methyl salicylate) aerosols; and explosive dust particulate was demonstrated. Continuous real-time Venturi-assisted monitoring of a large room (approximately 90 m2 area, 570 m3 volume) was demonstrated for a 60-min period without the remote sampling probe, exhibiting detection of chemical vapors and methyl salicylate at approximately 3 m stand-off distances within 2 min of exposure.

Outcomes of gastrointestinal defect closure with an over-the-scope clip system in a multicenter experience: An analysis of a successful suction method.

AIMTo demonstrate the clinical outcomes of a multicenter experience and to suggest guidelines for choosing a suction method.METHODSThis retrospective study at 5 medical centers involved 58 consecutive patients undergoing over-the-scope clips (OTSCs) placement. The overall rates of technical success (TSR), clinical success (CSR), complications, and procedure time were analyzed as major outcomes. Subsequently, 56 patients, excluding two cases that used the Anchor device, were divided into two groups: 14 cases of simple suction (SS-group) and 42 cases using the Twin Grasper (TG-group). Secondary evaluation was performed to clarify the predictors of OTSC success.RESULTSThe TSR, CSR, complication rate, and median procedure time were 89.7%, 84.5%, 1.8%, and 8 (range 1-36) min, respectively, demonstrating good outcomes. However, significant differences were observed between the two groups in terms of the mean procedure time (5.9 min vs 14.1 min). The CSR of the SS- and TG-groups among cases with a maximum defect size ≤ 10 mm and immediate or acute refractory bleeding was 100%, which suggests that SS is a better method than TG in terms of time efficacy. The CSR in the SS-group (78.6%), despite the technical success of the SS method (TSR, 100%), tended to decrease due to delayed leakage compared to that in the TG-group (TSR, CSR; 88.1%), indicating that TG may be desirable for leaks and fistulae with defects of the entire layer.CONCLUSIONOTSC system is a safe and effective therapeutic option for gastrointestinal defects. Individualized selection of the suction method based on particular clinical conditions may contribute to the improvement of OTSC success.