Cl Groups Research Articles

Secondary organic aerosol formation from p-dichlorobenzene under indoor environmental conditions

In indoor environments, the formation of secondary organic aerosols (SOAs) from gaseous volatile organic compounds (VOCs), which may have adverse health effects, has attracted attention. In particular, 1,4-dichlorobenzene (p-dichlorobenzene, p-DCB) is commonly used as a household insecticide in Japan, and its concentration may be high in indoor environments. Because p-DCB has highly reactive Cl groups, it is highly likely to be converted to SOAs under indoor environmental conditions. However, there have been no reports on the formation of SOAs from p-DCB. In this study, we investigated SOA formation from p-DCB gas under UV irradiation by volatilizing solid p-DCB and introducing it into a chamber as a gaseous substance, taking the influence of humidity and seed particles into account. Our results confirmed that SOAs, having a peak particle size of approximately 50 nm, were secondarily formed at a particle number concentration on the order of 1012 m−3. In addition, increased humidity and the coexistence of (NH4)2SO4 particles as seed particles further accelerated SOA formation. Furthermore, in an experiment with low-intensity UV irradiation under general indoor environmental conditions, we confirmed that SOAs were formed with a number concentration on the order of 1011 m−3, which is higher than the concentration in the general atmosphere. Therefore, an SOA formation reaction from p-DCB could occur at sufficient levels, even in general indoor environments.

Training with cognitive load improves performance under similar conditions in a real surgical task

BackgroundEnhancing cognitive load while performing a bimanual surgical task affects performance. Whether repeated training under this condition could benefit performance in an operating room was tested using a virtual reality simulator with cognitive load applied through two-digit math multiplication questions. Method11 subjects were randomized to Control, VR and VR + CL groups. After a pre-test, VR and VR + CL groups repeated the peg transfer task 150 times over 15 sessions with cognitive load applied only for the last 100 trials. After training, all groups took a post-test and two weeks later the retention test with and without cognitive load and the transfer task on a pig intestine of 150 cm long under cognitive load. Results and conclusionMixed ANOVA analysis showed significant differences between the control and VR and VR + CL groups (p = 0.013, p = 0.009) but no differences between the VR + CL and the VR groups (p = 1.0). GOALS bimanual dexterity score on transfer test show that VR + CL group outperformed both Control and VR groups (p = 0.016, p = 0.03).Training under cognitive load benefitted performance on an actual surgical task under similar conditions.

Aspects of Phosphaallene Chemistry: Heat-Induced Formation of 1,2-Dihydrophosphetes by Intramolecular Nucleophilic Aromatic Substitution and Photochemical Generation of Tricyclic Phosphiranes.

3H-Phosphaallenes are accessible on a new and facile route and show a fascinating chemical behavior. The thermally induced rearrangement of Mes*P═C═C(H)R' (R' = tBu, Ad) afforded by C-H activation, isobutene elimination, and C-C and P-H bond formation bicyclic 1-benzo-dihydrophosphetes (2) with PC3 heterocycles. DFT calculations suggest a mechanism with intramolecular nucleophilic aromatic substitution and replacement of an alkyl group by the nucleophilic α-C atom of the phosphaallene. These bicycles formed W(CO)5 complexes (3) or afforded 1,2-dihydrophosphetes with P-bound alkenyl groups by catalyst-free hydrophosphination of alkynes (4 and 5). The resulting bulky phosphines formed complexes with IrCp*Cl2, RuCl2, AuCl, or CuO3SCF3. The Ru atom is coordinated by the P atom and a phenyl group. Irradiation of TripP═C═C(H)tBu led by the insertion of the central C atom of the P═C═C group into the α-C-H bond of an iPr substituent and by C-C and P-C bond formation to a new isomer of phosphaallenes, 10, which features a strained PC2 heterocycle. It formed adducts with M(CO)5 (M = Cr, Mo, W) and AuCl and reacted with SO2Cl2 by cleavage of one of the phosphirane P-C bonds to yield PC4 or PC5 heterocycles. Hydrolysis yielded a PC5 compound with a P(O)Cl group.

Quantum confinement and edge effects on electronic properties of zigzag green phosphorene nanoribbons

First-principles density-functional theory calculations were performed to investigate quantum confinement and edge effects on electronic properties of zigzag green phosphorene nanoribbons (ZGPNRs) with edge chemical species including H, OH, F, Cl, O, and S for the ribbons width in the range of 0.5–3.7 nm. The ZGPNRs were obtained from relaxed two-dimensional green phosphorene monolayer with different cutting strategies and the most energetically favorable ribbon configuration was selected for further exploration of size and edge effects. It was found that the electronic properties of the ZGPNRs are strongly associated with the ribbon width and edge chemical species. They show either semiconducting or metallic features depending on the edge functionalization species. The ZGPNRs show semiconducting behavior with the edge species of H, OH, F, or Cl (Group I), while they exhibit metallic characteristics with pristine or O, S edges (Group II). The conduction band minimum and valence band maximum of the ZGPNRs with the Group I edge are primarily located at the inner P atoms and the edge P and functionalization atoms have little contribution. However, for the Group II edge, the electronic bands crossing the Fermi level are dominantly contributed by the edge atoms. It was also found that the band gap and work function of the ZGPNRs are sensitively tunable by varying ribbon width and edge functionalization species.

Long-term impacts of late-gestation maternal heat stress on growth performance, blood hormones and metabolites of newborn calves independent of maternal reduced feed intake

The objective of this study was to evaluate the effects of heat stress in late gestation independent of maternal reduced feed intake on performance, blood hormones and metabolites, and immune responses of dairy calves from birth through weaning. A total of 30 multiparous Holstein cows at 45 d before expected calving were randomly assigned to one of 3 groups: (1) thermal neutral (CL, n = 10) conditions with ad libitum feed intake (10% of refusals on an as-fed basis); (2) pair-fed thermal neutral (CLPF, n = 10) conditions to reduce feed intake to levels similar to the heat stress (HS) group while reared under thermoneutral conditions (80% of the CL group); or (3) heat stress (HS, n = 10) conditions with ad libitum feed intake. Pair-feeding was conducted to quantify the confounding effects of dissimilar feed intake. Calves (10/group) born to cows that were exposed to cooling (IU-CL), pair-feeding (IU-CLPF), or heat stress (IU-HS) were used from birth through weaning. After birth, all the calves were managed under identical conditions. IU-HS calves had lower birth weight, and hip height at birth and 14 d of age. Compared with IU-CL and IU-CLPF calves, IU-HS calves had lower serum concentration of IgG and apparent efficiency of IgG absorption but higher serum insulin concentrations. Cortisol concentration in serum was higher in IU-HS and IU-CLPF calves compared to IU-CL calves. The neutrophil percentage was lower in IU-CL calves than in IU-HS and IU-CLPF calves. Neutrophil-lymphocyte ratio was higher in IU-HS calves compared to IU-CLPF and IU-CL calves. The mRNA expression of TNFα of IU-HS calves was downregulated compared with IU-CL and IU-CLPF calves. In summary, maternal HS during late gestation reduces calf birth weight and dramatically alters blood hormones and metabolites, but its effect on immune system function was not independent of maternal reduced feed intake.

Impact of Different Stimulation Patterns of Neuromuscular Blockade Monitoring and Clinical Assessment on Intubation Time and Intensity of Hemodynamic Response During Rocuronium Induced Endotracheal Intubation

Introduction and aims: Typical autonomic response to endotracheal intubation manifests itself by increasing blood pressure and heart rate. The aim of this study as to evaluate whether different stimulation patterns of neuromuscular blockade monitoring techniques may impact hemodynamic response. Materials and Methods: Randomized, prospective, double blind study involved 60 patients who underwent elective abdominal surgery. Patients were randomly allocated into 3 groups. Anesthesia was induced with propofol-remifentanil and acceleromyography at adductor pollicis was established before rocuronium (0.6 mg/kg) was given to facilitate endotracheal intubation. Endotracheal intubation was initiated after 95% suppression of 0.1 Hz single twitch (ST group), complete disappearance of responses to train-of-four stimulation (TOF group) or after clinical criteria (good relaxation of the masseter muscle and the lower jaw, easy mask ventilation and the fact that 60 secs had elapsed since rocuronium was administered) were met (control-CL group). Blood pressure and heart rate were measured in five time points: after positioning the patient (HDbas), 30 s after propofol-remifentanyl (HD1), 30 s after rocuronium (HD2), 30 s (HD3) and 2 minutes following initiation (HD4) of endotracheal intubation. Results: The interval between administration of rocuronium and initiation of endotracheal intubation was significantly shorter in CL group (66.5 s), compared to TOF group (75.44 s) and ST group (83.75 s), (p < 0.001). There was statistically significant difference in systolic blood pressure at HD3 and HD4 time point between groups (p < 0.01). Post hoc analysis shows that these values of systolic blood pressure in CL group were significantly higher compared to the other two groups (p < 0.05). Also, systolic blood pressure after the fourth and fifth measurements were significantly higher compared to initial three measurements in CL group (p < 0.01). By comparing the heart rate at HD3and HD4 time points, significant difference between the groups was noted (p < 0.01). At HD3 time heart rate was significantly higher in CL group compared to other groups (p < 0.01). Additionally, at HD4 heart rate was significantly higher in CL group than in TOF group (p < 0.05) and ST group (p < 0.01). Also, heart rate was significantly increased at HD3 time point. Conclusion: Even though objective NMB monitoring prolongs intubating time, its use prevents vacillation of the hemodynamic response associated with endotracheal intubation.

Comparison of changes in the dental transverse and sagittal planes between patients treated with self-ligating and with conventional brackets.

ABSTRACTIntroduction: Several advantages have been established regarding the efficiency of self-ligating brackets (SL). In spite of some controversy surrounding this question in the literature, clinical results confirm that “arch development” requires fewer extractions. Objective: The objective of this study was to compare changes in the transverse and sagittal planes in patients treated with conventional ligating brackets (CL)as well as in patients treated with SL brackets and oversized arches. Methods: A sample was selected from a pool of 300 consecutive cases treated by a single clinician: 51 patients with SL brackets and oversized wires, and 55 with CL brackets. These two groups were compared with a control group of 20 patients. All plaster models were scanned and dental landmarks were measured to identify changes from commencement (T0) to conclusion (T1) of treatment. Lateral cephalograms were analyzed for changes in the lower incisor (IMPA) and the first lower molar distal angulation (MAng). Intraoperator reliability was tested with linear regression analysis. To assure all groups were comparable at T0, an ANOVA test with a 95%confidence interval (CI) was performed for all values. To assess changes from T0 to T1 in all groups, a Student’s t-test with 95% CI was used. Finally, results from the three groups were compared using an ANOVA-test (95% CI) and a post-hoc test. Results: Increases in all the transverse variables were recorded in the two groups treated (SL and CL), except for the lower intercanine distance in the SL group. IMPA difference from T0 to T1 was higher in the CL group, and molar distal angulation (MAng) took place in the SL group. Conclusions: Self-ligating brackets with oversized arches and conventional ligating brackets showed increases in all variables in the transverse plane, except for the SL group at the mandibular intercanine distance. In comparison with the CL group, fewer different IMPA values were observed in the SL group, in which distal molar angulation occurred.

High level of interleukin-33 in cancer cells and cancer-associated fibroblasts correlates with good prognosis and suppressed migration in cholangiocarcinoma.

Interleukin 33 (IL-33) promotes cholangiocarcinoma (CCA) genesis in a mouse model, however, its function in human CCA has not been clearly understood. This study was aimed to investigate IL-33 level in CCA tissues and its clinicopathological correlations. The results revealed that IL-33 was found in both cancer cells and stromal cancer-associated fibroblast (CAFs) staining patterns which were divided into high (CH) and low level (CL) in cancer cells; and presence (FP) and absence (FA) in CAFs. Kaplan-Meier analysis showed that patients in the CL group were significantly correlated with a short 2-year survival time (P = 0.027). The CL/FP group had a shorter survival time compared to the other groups with statistical significance for 2-year (P = 0.030) and 5-year (P = 0.023) survivals. In contrast, CH/FP patients had significantly greater 2-year (P = 0.003) and 5-year (P = 0.003) survivals. Univariate and multivariate analysis confirmed that CL/FP was a significantly independent risk factor whereas CH/FP was a significant protective factor in CCA patients. High IL-33 expressing CCA cells had low migration, but they showed increased migration when IL-33 expression was knocked down. The low level of recombinant human IL-33 (rhIL-33) (0.002 - 2 ng/ml) could promote CCA cell migration, in contrast to the suppressive effect at a high dose (20 - 200 ng/ml). In conclusion, the combination of high IL-33 level in cancer cells and CAFs is a potentially good prognosis marker in CCA patients. The in vitro migration suppressive effect of IL-33 may be the potential mechanism supporting its role as a good prognostic marker in CCA patients. The obtained results strengthen IL-33 as a promising predictor and therapeutic target for CCA.

Theoretical insights into the intermolecular and mechanisms of covalent interaction of Flutamide drug with COOH and COCl functionalized carbon nanotubes: A DFT approach

In this study, it is attempted to scrutinize the noncovalent interaction and two mechanisms of covalent between Flutamide anti-cancer drug (FLU) and functionalized carbon nanotubes (f-CNT) employing density functional theory (DFT) calculations regarding their geometries, binding energies and topological features of the electron density in the water solution. For designed noncovalent interactions, binding energies, natural bond orbital (NBO), atom in molecule (AIM) and quantum molecular descriptors analyses were applied for further understanding of the adsorption process. The computed theoretical results confirmed that binding of Flutamide molecule with functionalized CNT is thermodynamically suitable and among two considered systems containing COOH functionalized CNT (NTCOOH) and COCl functionalized CNT (NTCOCl), the NTCOOH revealed more binding energy value which suggests it as a favorable system as a drug delivery within biological and chemical systems (noncovalent). NTCOOH and NTCOCl can bond to the NH group of flutamide through OH (COOH mechanism) and Cl (COCl mechanism) groups, respectively. Finally, to obtain the values of activation energies, the activation enthalpies and the activation Gibbs free energies of two considered pathways different calculations were performed and the results have been compared with each other. Numerical studies for calculating activation parameters related to the COOH mechanism show higher values than those related to the COCl mechanism and therefore COOH mechanism can be suitable for noncovalent functionalization. These results could be generalized to other similar drugs.

Preparation of hollow SiC ceramic fibre from polycarbosilane fibre by diffusion-controlled cross-linking method

ABSTRACTCross-linking is favourable for increasing ceramic yield and avoiding melting or deformation of SiC ceramic precursor polycarbosilane (PCS) during pyrolysis. In order to achieve hollow SiC fibre, PCS fibre with a limited cross-linking depth was prepared by chlorinating the Si–H group in the outer layer of PCS fibre followed by hydrolysis and condensation of the formed Si–Cl group. The chlorination was implemented through a gas–solid reaction between Cl2 and PCS fibre. Based on the results of energy-dispersive spectrometer and attenuated total reflectance–Fourier transform infrared spectroscopy, the diffusion-controlled chlorination reaction was confirmed. During hydrolysis, the catalysis of ammonia gas was necessary. According to the results of dissolution and degradation experiments, cross-linked PCS outer layer formed after chlorination, hydrolysis and condensation, and the outer layer had higher ceramic yield than the core part. After pyrolysis, SiC fibre with hollow morphology was formed. By adjusting the chlorination degree, the morphology of resulting hollow SiC fibre could be modified.

Dietary chloride levels affect performance and eggshell quality of laying hens by substitution of sodium sulfate for sodium chloride

The objective of this study was to evaluate the effect of dietary chloride (Cl) levels on performance, eggshell mechanical quality, and ultrastructure in layers based on the substitution of sodium chloride (NaCl) by sodium sulfate (Na2SO4). Three hundred sixty Jing Brown laying hens aged 43 wk were randomly divided into 5 groups and fed with corn–soybean meal diets containing 0.06, 0.10, 0.15, 0.20, and 0.25% total Cl inclusion. Every group had 8 replicates of 9 birds each. The feeding trial lasted for 12 wk. The results showed dietary 0.06% Cl due to complete substitution of NaCl by Na2SO4, depressed performance (P < 0.05) from 45 to 54 wk of age, increased serum creatinine level (P < 0.05), and caused visible renal tubular atrophy. Dietary Cl levels quadratically affected breaking strength, thickness, and weight of eggshell (P < 0.05). Better eggshell quality could be obtained when NaCl was partly replaced by Na2SO4 in laying hen diets maintaining Cl level at 0.10 or 0.15%. Moreover, the eggshell ash content was affected by Cl levels in a quadratic (P < 0.001) manner, with higher values observed in the 0.10 and 0.15% Cl groups (P < 0.05). Besides, the eggshell ultrastructural data showed that the total thickness and effective thickness significantly increased (P < 0.05) and mammillary thickness decreased (P < 0.05) in the group of dietary 0.15% Cl compared with the groups of 0.06 and 0.25% Cl. In conclusion, the complete substitution of dietary NaCl by Na2SO4 may induce Cl deficiency and depress laying performance and eggshell quality. Na2SO4 could partly replace NaCl in diets for laying hens (43–54 wk of age) without adverse effects on performance at the dietary Cl level from 0.10 to 0.25%. Better eggshell quality could be obtained when NaCl was partly replaced by Na2SO4 in laying hen diets maintaining Cl level at ∼0.15%.

β3-Adrenergic receptor blockade reduces mortality in endotoxin-induced heart failure by suppressing induced nitric oxide synthase and saving cardiac metabolism.

The β3-adrenergic receptor (β3AR) is related to myocardial fatty acid metabolism and its expression has been implicated in heart failure. In this study, we investigated the role of β3AR in sepsis-related myocardial dysfunction using lipopolysaccharide (LPS)-induced endotoxemia as a model of cardiac dysfunction. We placed mice into three treatment groups and treated each with intraperitoneal injections of the β3AR agonist CL316243 (CL group), the β3AR antagonist SR59230A (SR group), or normal saline (NS group). Survival rates were significantly improved in the SR group compared with the other treatment groups. Echocardiography analyses revealed cardiac dysfunction within 6-12 h of LPS injections, but the outcome was significantly better for the SR group. Myocardial ATP was preserved in the SR group but was decreased in the CL-treated mice. Additionally, quantitative PCR analysis revealed that expression levels of genes associated with fatty acid oxidation and glucose metabolism were significantly higher in the SR group. Furthermore, the expression levels of mitochondrial membrane protein complexes were preserved in the SR group. Electron microscope studies showed significant accumulation of lipid droplets in the CL group. Moreover, inducible nitric oxide synthase (iNOS) protein expression and nitric oxide were significantly reduced in the SR group. The in vitro study demonstrated that β3AR has an independent iNOS pathway that does not go through the nuclear factor-κB pathway. These results suggest that blockading β3AR improves impaired energy metabolism in myocardial tissues by suppressing iNOS expression and recovers cardiac function in animals with endotoxin-induced heart failure.NEW & NOTEWORTHY Nitric oxide production through stimulation of β3-adrenergic receptor (β3AR) may improve cardiac function in cases of chronic heart failure. We demonstrated that the blockade of β3AR improved mortality and cardiac function in endotoxin-induced heart failure. We also determined that LPS-induced inducible nitric oxide synthase has a pathway that is independent of nuclear factor-κB, which worsened cardiac metabolism and mortality in the acute phase of sepsis. Treatment with the β3AR antagonist had a favorable effect. Thus, the blockade of β3AR could offer a novel treatment for sepsis-related heart failure.

Catalytic hydrolysis of cellulose to total reducing sugars with superior recyclable magnetic multifunctional MCMB‐based solid acid as a catalyst

AbstractBACKGROUNDEffective cellulose hydrolysis has a huge potential for producing high value‐added biomass‐based platform chemicals, such as glucose, hydroxymethylfurfural, levulinic acid, and total reducing sugars (TRS). Particularly, a magnetic multifunctional solid acid catalyst (Fe3O4/Cl–MCMB–SO3H) was synthesized by loading the active groups on the magnetic mesocarbon microbead (MCMB) derived from the co‐calcination of coal tar pitch and ferroferric oxide, which was applied as a catalyst in the conversion of cellulose into TRS.RESULTSGiven the superior properties of MCMB, a novel magnetic MCMB‐based solid acid with cellulose‐binding domain (–Cl group) and catalytic domain (–SO3H group) was successfully prepared. Results indicated that this catalyst exhibited superior catalytic activity, recyclability and regenerability, and easy separation from the reactant. The acidic densities of –SO3H and –Cl in Fe3O4/Cl–MCMB–SO3H reached 1.77 and 1.32 mmol/g, respectively. The 68.6% TRS yield can be obtained from cellulose at 140 °C for 3 h in distilled water by using Fe3O4/Cl‐MCMB‐SO3H as the catalyst. The TRS yield still reached 61.1% after the catalyst was used six times. Importantly, through catalyst regeneration, the –SO3H density and TRS yield still reached 1.69 mmol/g and 67.3%, indicating that the catalyst exhibited excellent regenerability.CONCLUSIONSuch multifunctional magnetic catalyst would be a promising catalyst in the conversion of cellulose into biofuels, which was attributed to the efficient catalytic performance, magnetism, and excellent recyclability and regenerability. © 2019 Society of Chemical Industry

Improving the physical properties of clay using Sinabung volcanic and rice husk ash with UCT and CBR

Stabilization can be done by adding something to the soil in order to improve its strength and bearing capacity. One of the efforts to stabilize the soil is to add certain chemicals so that the soil will become solid. The additive materials used in this research are Rice Husk Ash (ASP) and Volcanic Ash (AGV) which is obtained from the eruption of Mt. Sinabung. The purpose of this research is to find index properties value as the effect of adding 2%, 4%, 6%, 8% Volcanic Ash and 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20% Rice Husk Ash on clay, to find the maximum compressive strenght value with UCT (Unconfined Compression Test), to find the CBR (California Bearing Ratio) value as the effect of adding the stabilization agents, and also to find the optimum content of adding Rice Husk Ash. According to the result of this research, the soil has 34.43% water content, 2.65 specific gravity, 47.33% liquid limit, 29.88% plasticity index, and 1.42 kg/cm2 compressive strength. Based on the classification system of Unified Soil Classification System (USCS), this soil is included in the group of CL which is inorganic clay with low to medium plasticity. Meanwhile based on the classification system of American Association of State Highway and Transportation Officials (AASHTO), this soil could be classified as type of soil A-7-6. The highest compressive strength value is obtained from the addition of 8% Sinabung ash and 2% Rice Husk Ash which is 3.17 kg/cm and the optimum CBR value also obtained from the addition of 8% Sinabung ash and 2% Rice Husk Ash which is 8.53%.

Fluorescence Properties and Exciplex Formation of Emissive Naphthyridine Derivatives: Application as Sensors for Amines.

Water-soluble donor-acceptor-type fluorophore 15Nap-Cl having two trifluoromethyl groups and a Cl group on a 1,5-aminonaphthyridine framework was prepared. Fluorophore 15Nap-Cl showed strong solvatochromic fluorescence, and, as the solvent polarity increased, a bathochromic shift was observed accompanied by an increase in the fluorescence quantum yield. In addition, in the presence of amines such as ethylamine, diethylamine, and aniline, further considerable bathochromic shifts in the fluorescence were observed. Density functional calculations identified the source of the fluorescence behavior as exciplex formation between 15-Nap-Cl and the corresponding amine. The fluorescence behavior was exploited to fabricate a sensor that can identify various primary, secondary, and tertiary amines.

Synthesis, Cytotoxic, Antibacterial and Free Radical Scavenging Activities of Schiff Bases Derived from 1,2,4-Triazole

: A series of new 1,2,4-triazole Schiff bases incorporating a chlorinated indole moiety were prepared from the condensation reaction of 4-amino-5-mercapto-3-[(5-chloro-2-methyl-1H-indol-3- yl)methyl]1,2,4-triazole with substituted benzaldehydes in the presence of (+)-tartaric acid as an acidic catalyst. The structures of Schiff bases were elucidated by FTIR, NMR and mass spectral data. The cytotoxic, antibacterial and free radical scavenging activities of Schiff bases were performed using MTT, 96-well microbroth dilution and DPPH assays, respectively. Schiff bases 3k and 3l with both electron donating groups at meta and para positions of the phenyl ring demonstrated higher cytotoxic activity against COLO-205 and A549 cell lines. On the other hand, Schiff base 3f comprising p-chlorophenyl substituent exhibited significant inhibition against Bacillus cereus and Staphylococcus aureus at MIC 3.91 μg/ml and 15.63 μg/ml, respectively. The results of the free radical scavenging activity revealed that Schiff bases with the presence of a Cl or OCH3 group in the para position of the phenyl ring act as a better antioxidant than BHT.

Study on the hydrolysis of cellulose with the regenerable and recyclable multifunctional solid acid as a catalyst and its catalytic hydrolytic kinetics

The regenerated solid acid (Cl-MCMB-SO3H) catalyst containing bifunctional groups, namely, –SO3H and –Cl, was prepared using mesocarbon microbeads (MCMB) with numerous aromatic constituents. The acidic densities of –SO3H and –Cl in the as-prepared Cl-MCMB-SO3H reached 1.98 and 1.72 mmol/g, respectively. The total reducing sugar (TRS) yield of 70.3% was achieved at 130 °C for 3 h in distilled water with Cl-MCMB-SO3H solid acid as a catalyst. The analysis of hydrolytic kinetic model showed that the activation energy (Ea) of cellulose hydrolysis by using Cl-MCMB-SO3H was 89.4 kJ/mol, which was considerably lower than that of MCMB-SO3H (109.2 kJ/mol). Thus, the existence of –Cl group was not only beneficial in forming hydrogen bonds with cellulose but also aided in reducing the Ea value of cellulose hydrolysis. The TRS yield only decreased by 9.6% with Cl-MCMB-SO3H solid acid after it was recycled five times. More importantly, the TRS yield still reached 70.1% and 69.7% through the first and second Cl-MCMB-SO3H regeneration, respectively, demonstrating the excellent regenerability of the solid acid catalyst. The multifunctional MCMB-solid acid was prepared and used for the catalytic hydrolysis of cellulose, which exhibited excellent catalysis, regenerability, and recyclability performances, and the introduction of –Cl group not only facilitated the formation of hydrogen bonds with cellulose but also dramatically decreased the activation energy.

Understanding the Influence of Electron-Donating and Electron-Withdrawing Substituents on the Anticorrosive Properties of Imidazole: A Quantum-Chemical Approach

The nature and position of electron-donating and electron-withdrawing substituents are believed to play a major role on the corrosion inhibition properties in small organic molecules. In this study, the substituent effect on the imidazoles anticorrosive properties has been explored theoretically using the density functional theory performed at the B3LYP/6-311++G(d,p) level. A wide spectrum of substituents including NH2, COOH, I, Br, Cl, F, CN, F, OH, OCH3, NO2, C6H5 and SH groups has been explored in the aqueous medium, and the different possible substitution positions have been investigated. Frontier molecular orbitals and quantum-chemical reactivity descriptors were calculated for the neutral and protonated forms of imidazole derivative. While the energy gaps, electronegativity and global hardness values showed a very good agreement with the corrosion inhibition performance reported from previous experimental work for imidazoles, the electrophilicity and molecular volume parameters were found less consistent. This study concluded that the amino and nitro groups, in particular those at C2 and C4 positions, exhibit prominent corrosion inhibition performance. The electron-releasing phenyl and methoxy substituents could also play a potential role in enhancing the anticorrosive properties of imidazole.

Definitive Tumor Resection after Myeloablative High Dose Chemotherapy Is a Feasible and Effective Option in the Multimodal Treatment of High-Risk Neuroblastoma: A Single Institution Experience

Background/PurposeThe delayed local treatment approach (DL) in high-risk neuroblastoma (HR-NB) refers to the process in which tumor resection is performed after the completion of all the courses of chemotherapy, including myeloablative high-dose chemotherapy (HDC). Alternatively, in the conventional local treatment approach (CL), tumor resection is performed during induction chemotherapy. In this study, we compared the surgical outcomes in HR-NB patients treated by CL and DL. MethodForty-seven patients with abdominal HR-NB underwent primary tumor resection from 2002 to 2018. The timing of surgery was generally determined by following the trials and guidelines available at the time. The outcomes and surgical complications between the two strategies were compared. ResultOperation time, blood loss, and postoperative WBC counts were lower in the DL group (n = 25) when compared to the CL group (n = 22), statistical significance notwithstanding. Major vascular structures were less frequently encased in the DL group tumors, while immediate surgical complications were significantly more frequent in the CL group (P < 0.05). Furthermore, the 3-year EFSs were 50.0% and 53.9% in the DL and CL groups, respectively. ConclusionDL appears to be a feasible and effective treatment option for HR-NB. Nonetheless, further verifications using larger cohorts are warranted. Level of evidenceTreatment study, Level III.

Novel per-oral endoscopic myotomy method preserving oblique muscle using two penetrating vessels as anatomic landmarks reduces postoperative gastroesophageal reflux.

One of the main concerns related to peroral endoscopic myotomy (POEM) is postoperative gastroesophageal reflux (GER). The two penetrating vessels (TPVs) that are found at the boundary between the circular and oblique muscles in the posterior cardia wall have been suggested to be a good indicator of the optimal distal extent of POEM. However, the effect of performing myotomy using the TPVs as an anatomical reference on the frequency of post-POEM GER has not been studied. This study involved consecutive patients who underwent POEM for the treatment of achalasia between April 2015 and June 2017. All enrolled patients underwent POEM in the 5 o'clock position and were divided into two groups: the conventional line group (CL group, n=31), in which the TPVs were not exposed during submucosal tunnel dissection in the cardia, and the TPVs line group (TPVs group, n=83), in which the TPVs were exposed and gastric myotomy was performed along the right side of the TPVs to preserve the oblique muscle. Examinations for post-POEM GER were conducted 3months after the POEM. The frequency of grade B or higher reflex esophagitis was 26/83 (31.3%) in the TPVs group and 18/31 (58.1%) in the CL group (P=0.017). Nine of 83 patients (10.8%) had GER symptoms in the TPVs group, and six of 31 (19.4%) had GER symptoms in the CL group (P=0.23). The novel myotomy method preserving oblique muscle using TPVs as anatomical landmarks significantly reduced the frequency of post-POEM GER.