Multi-analyte fluorescence sensing based on a post-synthetically functionalized two-dimensional Zn-MOF nanosheets featuring excited-state proton transfer process.

Covalent post-synthetic modification of metal-organic frameworks (MOFs) represents an underexplored but promising avenue for allowing the addition of specific fluorescent recognition elements to produce the novel MOF-based sensory materials with multiple-analyte detection capability. Here, an excited-state proton transfer (ESPT) active sensor 2D-Zn-NS-P was designed and constructed by covalent post-synthetic incorporation of the excited-state tautomeric 2-hydroxypyridine moiety into the ultrasonically exfoliated amino-tagged 2D Zn-MOF nanosheets (2D-Zn-NS). The water-mediated ESPT process facilitates the highly accessible active sites incorporated on the surface of 2D-Zn-NS-P to specifically respond to the presence of water in common organic solvents via fluorescence turn-on behavior, and accurate quantification of trace amount of water in acetonitrile, acetone and ethanol was established using the as-synthesized nanosheet sensor with the detection sensitivity (<0.01% v/v) superior to the conventional Karl Fischer titration. Upon exposure to Fe3+ or Cr2O72-, the intense blue emission of the aqueous colloidal dispersion of 2D-Zn-NS-P was selectively quenched even in the coexistence of common inorganic interferents. The prohibition of the water-mediated ESPT process and local emission, induced by the coordination of ESPT fluorophore with Fe3+ or by Cr2O72- competitively absorbs the excitation energy, was proposed to responsible for the fluorescence turn-off sensing of the respective analytes. The present study offers the attractive prospect to develop the ESPT-based fluorescent MOF nanosheets by covalent post-synthetic modification strategy as multi-functional sensors for detection of target analytes.

Monthly variations of groundwater arsenic risk under future climate scenarios in 2081-2100.

The seasonal variations of shallow groundwater arsenic have been widely documented. To gain insight into the monthly variations and mechanisms behind high groundwater arsenic and arsenic exposure risk in different climate scenarios, the monthly probability of high groundwater arsenic in Hetao Basin was simulated through random forest model. The model was based on arsenic concentrations obtained from 566 groundwater sample sites, and the variables considered included soil properties, climate, topography, and landform parameters. The results revealed that spatial patterns of high groundwater arsenic showed some fluctuations among months under different future climate scenarios. The probability of high total arsenic and trivalent arsenic was found to be elevated at the start of the rainy season, only to rapidly decrease with increasing precipitation and temperature. The probability then increased again after the rainy season. The areas with an increased probability of high total arsenic and trivalent arsenic and arsenic exposure risk under SSP126 were typically found in the high-arsenic areas of 2019, while those with decreased probabilities were observed in low-arsenic areas. Under SSP585, which involves a significant increase in precipitation and temperature, the probability of high total arsenic and trivalent arsenic and arsenic exposure risk was widely reduced. However, the probability of high total arsenic and trivalent arsenic and arsenic exposure risk was mainly observed in low-arsenic areas from SSP126 to SSP585. In conclusion, the consumption of groundwater for human and livestock drinking remains a threat to human health due to high arsenic exposure under future climate scenarios.

The geochemical stability of typical arsenic-bearing sinter in the Tibetan plateau: Implications from quantitative mineralogy.

High­arsenic (As) sinter deposited from geothermal water is a potentially overlooked hazardous matrix and there remain substantial gaps in our comprehension of the stability of As sequestered within it. In this study, qualitative and quantitative analysis of the mineralogy of As-bearing sinter was conducted by Mineral Liberation Analyzer (MLA) in geothermal areas of the Tibetan Plateau to reveal the geochemical stability of As. Our results indicated that the contents of As in sinter were 3 orders of magnitude higher than the local soil. The dominant host minerals of As were calcite (40.9 %), thenardite (22.5 %), calcium silicate (13.0 %), and halite (8.1 %). Additionally, it was found that a relatively higher As bioavailability was extracted by ethylene diamine tetraacetic acid (EDTA), with a leaching rate of 41.2 %. Notably, the X-ray diffraction (XRD) showed that the thenardite and halite were decomposed after the leaching. The combination of mineralogy and geochemistry data suggested that calcite and calcium silicate were a crucial mechanism for As retention in sinter, while the dissolution of saline minerals (e.g., thenardite, halite, and calcium chloride) served as the primary sources for As release. This finding unveils the potential risks and mechanisms associated with high-As sinter, providing scientific guidance for risk management of sinter.

Comparison of invisalign mandibular advancement and twin-block on upper airway and hyoid bone position improvements for skeletal class II children: a retrospective study.

BACKGROUND: This study is to evaluate and compare the improvement of upper airway morphology and hyoid bone position in children with Class II mandibular retrusion treated with Invisalign mandibular advancement (MA) and Twin-Block (TB) appliances, utilizing cone beam computed tomography (CBCT). METHODS: 32 children aged between 8 and 11.5 years old were included in this study, with an average age of 10.2 years old. These children were divided into two groups, MA and TB, with 16 children in each group. Changes in upper airway morphology and hyoid bone position before and after treatment were analyzed using CBCT. RESULTS: (1) Changes in upper airway before and after treatment: the oropharynx volume (Or-V), the oropharynx minimum cross-sectional area (Or-mCSA), the hypopharynx volume (Hy-V), and the hypopharynx minimum cross-sectional area (Hy-mCSA) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05) compared to pre-treatment status. (2) Changes in hyoid bone position before and after treatment: The distances between H point and third cervical vertebra (H-C3), H point and pogonion (H-RGN), H point and mandibular plane (H-MP), H point and Frankfort horizontal plane (H-FH), H and S point (H-S), and H point and palatal plane (H-PP) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05). CONCLUSION: Both MA and TB appliances effectively improved the structural narrowness of the upper airway and reduced respiratory resistance, thus improving breath quality. However, MA showed more effectiveness in improving the narrowest part of the hypopharynx compared to TB. Both appliances also promoted anterior downward movement of the hyoid bone, which opens the upper airway of the oropharynx and hypopharynx and helps the upper airway morphology return to normal range.

Characteristics, sources, and risk assessment of thallium and associated with metal(loid)s in the Yarlung Tsangpo River Basin, southern Tibetan Plateau.

The Tibetan Plateau (TP) is known as the water tower of Asia, and the water quality has long been a focus of public concern, especially in the Yarlung Tsangpo River Basin (YTRB), a unique area that is climate-sensitive, geologically complex, eco-fragile, and densely populated. Thallium (Tl) is a typical metal that is more toxic than Pb, Cd, and As and often occurs in sulfide minerals. Although large-scale polymetallic sulfide mineralization developed in the YTRB, the geochemical dispersion and potential risk of Tl in aquatic environments of the YTRB remain poorly understood. In this study, the concentration, distribution, source, and health risk of Tl and associated metal(loid)s in the hot springs and surface water in the YTRB were systematically analyzed. The results showed that the trace elements (Cd, Cr, Zn, Cu, Al, Sr, Ni, Co, Mn, Pb) in water environments are within the recommended limits, except for Tl and As. Principal component analysis (PCA) and correlation analysis (CA) showed that the elements of Tl and As were positively related to each other in either both hot spring water and surface water, indicating their common origin. Spatial variations suggested that high levels of Tl and As observed in the north YTRB, which may be relevant to the reduction-dissolution of Tl (As)-bearing minerals and the magmatic hydrothermal system formed in the shallow part of the northern YTRB. Furthermore, source apportionment identified natural sources of Cu, Ni, Cr, Co, Mn, Zn, and Cd and anthropogenic inputs of Al and Pb. Exposure assessment studies have found that ingestion is the primary route of As and Tl exposure to local population, and balneological and bathing purposes do not constitute a human health concern. This study offers valuable insights into the risk of naturally occurring Tl enrichment being hidden in As-rich hydrosphere in the YTRB and other regions with similar geoenvironmental contexts.

The trajectory patterns of single HIV-1 virus-like particle in live CD4 cells: A real time three-dimensional multi-resolution microscopy study using encapsulated nonblinking giant quantum dot.

BACKGROUND: The exploration of virology knowledge was limited by the optical technology for the observation of virus. Previously, a three-dimensional multi-resolution real-time microscope system (3D-MRM) was developed to observe the uptake of HIV-1-tat peptide-modified nanoparticles in cell membrane. In this study, we labeled HIV-1 virus-like particles (VLPs) with passivated giant quantum dots (gQDs) and recorded their interactive trajectories with human Jurkat CD4 cells through 3D-MRM. METHODS: The labeled of gQDs of the HIV-1 VLPs in sucrose-gradient purified viral lysates was first confirmed by Cryo-electronic microscopy and Western blot assay. After the infection with CD4 cells, the gQD-labeled VLPs were visualized and their extracellular and intracellular trajectories were recorded by 3D-MRM. RESULTS: A total of 208 prime trajectories was identified and classified into three distinct patterns: cell-free random diffusion pattern, directional movement pattern and cell-associated movement pattern, with distributions and mean durations were 72.6%/87.6 s, 9.1%/402.7 s and 18.3%/68.7 s, respectively. Further analysis of the spatial-temporal relationship between VLP trajectories and CD4 cells revealed the three stages of interactions: (1) cell-associated (extracellular) diffusion stage, (2) cell membrane surfing stage and (3) intracellular directional movement stage. CONCLUSION: A complete trajectory of HIV-1 VLP interacting with CD4 cells was presented in animation. This encapsulating method could increase the accuracy for the observation of HIV-1-CD4 cell interaction in real time and three dimensions.

Excess-electron capture and energy transfer to bulk water for aqueous DNA nucleotide.

We performed QM/MM simulations to investigate excess-electron attachment to four aqueous DNA nucleotide anions (dRT-). The negative QM/MM vertical electron affinities (-0.86 to -0.59 eV) reveal that aqueous dRT- anions improbably capture the excess electron near 0 eV. Comparing with the calculations in the gas phase and without the background charges, it can be found that first-shell water molecules have a larger contribution to the promotion of the ability of the excess-electron capture and the bulk-water polarization has a small effect on vertical electron affinities. The phosphate group hampers the attachment of the very low-energy excess electron to aqueous dRT-. The large adiabatic electron affinities (1.45-1.96 eV) and vertical detachment energies (1.92-2.44 eV) reveal that stable dRT2- dianions could be formed after dRT- anions catch the higher-energy excess electron (>0.59 eV). We computed the energy changes in the dRT2- structural relaxations. The QM-region conformational changes cause small energy alterations (-0.28 to 0.35 eV). The QM/MM energy decreases are 2.31-2.73 eV which mainly come from QM computations (3.49-4.00 eV) embedded in the background charges. The analysis of excess-electron distributions indicates that the polarization of bulk water and structural relaxations of dianions induce the excess-electron redistributions in the QM region and produce large QM-energy decreases. The MM energy changes are -1.27 to -1.11 eV for four aqueous dianions. The negative values demonstrate that the energy of the MM region would increase in dRT2- structural relaxations. In contrast with the values of the polarized QM computations, about 30% of the energy released by the QM region is transferred to bulk water in the MM region. The large energy dissipation probably suppresses DNA damage by the low-energy electron.

Parabolic Potential Surfaces Localize Charge Carriers in Nonblinking Long-Lifetime "Giant" Colloidal Quantum Dots.

Materials for studying biological interactions and for alternative energy applications are continuously under development. Semiconductor quantum dots are a major part of this landscape due to their tunable optoelectronic properties. Size-dependent quantum confinement effects have been utilized to create materials with tunable bandgaps and Auger recombination rates. Other mechanisms of electronic structural control are under investigation as not all of a material's characteristics are affected by quantum confinement. Demonstrated here is a new structure-property concept that imparts the ability to spatially localize electrons or holes within a core/shell heterostructure by tuning the charge carrier's kinetic energy on a parabolic potential energy surface. This charge carrier separation results in extended radiative lifetimes and in continuous emission at the single-nanoparticle level. These properties enable new applications for optics, facilitate novel approaches such as time-gated single-particle imaging, and create inroads for the development of other new advanced materials.

Analysis of Pediatric Oncology Nursing Research in Mainland China, 2008-2018.

BACKGROUND: Up-to-date research from low- and middle-income countries is needed to inform local pediatric cancer nursing care and share best practices from these settings. Access to all current Chinese-language publications on pediatric oncology nursing research is limited because of a language barrier. OBJECTIVE: The aim of this study was to document the volume, type of research study, and yearly and geographical distribution of published pediatric oncology nursing research in Mainland China and evaluate their content and quality. METHODS: A systematic search was performed for published pediatric oncology research conducted by nurses in Mainland China (2008-2018), using 3 English databases and 3 Chinese databases. Included articles were evaluated using the Johns Hopkins Nursing Evidence-Based Practice Research Evidence Appraisal for strength and quality of evidence. RESULTS: A total of 133 articles were included: 106 in Chinese and 27 in English. Most studies showed level III evidence (88/133) and were rated as good quality (81/133). The most frequently researched topics were psychosocial care, clinical nursing practice, and psychometric testing, which accounted for 63.2% of all publications. CONCLUSIONS: Progress in pediatric oncology nursing research capacity among Mainland China is promising. To gain higher-quality evidence and make existing evidence transferable for nursing practice, optimization of specific research topics is still needed. IMPLICATIONS FOR PRACTICE: In Mainland China, developing interventions to address the symptoms of children with cancer and caregivers' psychosocial issues based on local nursing research should be prioritized. Some synthesized findings of this review may serve as guidance for the future of pediatric oncology nursing science in similar settings.

Multifactorial analysis of renal anemia-associated substandard hemoglobin levels and prevalence of anemia in patients on maintenance hemodialysis in Liaoning Province: a cross-sectional study.

BACKGROUND: In hemodialysis (HD) patients, anemia is greatly improved due to regular weekly use of iron and erythropoietin (EPO), but a large number of patients still show persistent anemia. We do a survey to elucidate the influencing factors that contribute to the failure of hemoglobin (Hb) to meet the standard and provide epidemiological data reference for promoting the recognition of renal anemia and improving the treatment effect of renal anemia. METHODS: The clinical data of End-Stage Renal Disease (ESRD) HD patients in 22 tertiary hospital HD centers in Liaoning Province from September 2021 to June 2022 were collected by convenient sampling. According to the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) anemia diagnostic criteria. The standard of Hb compliance: Hb ≥110 g/L is considered as Hb compliant, and Hb <110 g/L as Hb non-compliant. The factors influencing Hb up-to-standard in ESRD HD patients and their correlations were analyzed by comparison between the two groups. RESULTS: The results of this study showed that among the 1,652 ESRD patients investigated in Liaoning Province, the prevalence rate of anemia was 89.29% (1,475/1,652), and the Hb compliance rate was 46.25% (764/1,652). The Hb compliance rate in maintenance hemodialysis (MHD) patients with different primary diseases was statistically significant (P<0.05). Compared with the Hb non-standard group, the gender, dialysis access, HD frequency, concurrent infection, primary disease of ESRD patients, red blood cell (RBC) count, hematocrit (HCT), mean RBC Hb concentration, mean RBC Hb content, platelet (PLT), albumin (ALB), total protein (TP), serum creatinine (Cr), serum calcium (Ca), serum potassium (K), ferritin (Fer), serum iron (SI), and transferrin (TRE) saturation were significantly different between both groups (P<0.05). Adrenaline was an independent risk factor affecting Hb failure in ESRD patients (OR =1.001, 95% CI: 1.000-1.002); dialysis frequency (OR =0.726, 95% CI: 0.601-0.878), ALB (OR =0.959, 95% CI: 0.929-0.990), TP (OR =0.982, 95% CI: 0.968-0.996), serum Cr (OR =0.959, 95% CI: 0.929-0.999), and SI (OR =0.961, 95% CI: 0.940-0.982) were protective factors affecting Hb failure in ESRD patients (P<0.05). Pearson correlation analysis showed that ALB, TP, serum Cr, serum Ca, serum K, SI, and TRE saturation were positively correlated with Hb (P<0.05). CONCLUSIONS: The anemia rate of ESRD patients treated with MHD in Liaoning Province is high. Based on the results, increasing the frequency of dialysis can improve anemia. Parathyroid hormone levels need to be controlled.

Variation in rectoanal inhibitory reflex after laparoscopic intersphincteric resection for ultralow rectal cancer.

AIM: The aim was to evaluate the physiological variation in rectoanal inhibitory reflex (RAIR) after laparoscopic intersphincteric resection (Lap-ISR) for ultralow rectal cancer. METHOD: This was a retrospective study that included 56 patients who underwent Lap-ISR from a prospectively collected database. The RAIR was examined preoperatively and up to 12 months after ileostomy closure. The primary outcome included physiological variation in RAIR and its difference between partial, subtotal and total ISR. The secondary outcome was its correlation with functional outcome. RESULTS: The reflex was present in 95% (53/56) of patients preoperatively, in 36% (20/56) before ileostomy closure, in 48% (27/56) at 3-6 months and in 61% (34/56) at 12 months after ileostomy closure. The elicited volume of RAIR was significantly increased at 12 months after ileostomy closure than at baseline (P = 0.005), but its duration and amplitude did not differ significantly. There was no significant difference in the reflex recovery between the ISR groups (partial vs. subtotal vs. total: 65% vs. 63% vs. 44%, P = 0.61). At 12 months after ileostomy closure, the RAIR-present group had favourable functional results and patient satisfaction (P < 0.05). Major faecal incontinence was found in 82% of patients in the RAIR-absent group. CONCLUSION: The RAIR is abolished in the majority of patients after Lap-ISR, but a time-dependent recovery could be observed in more than half of the patients. The reflex recovery is not influenced by the resection grade of the internal sphincter. However, persistent loss of the RAIR correlates with worse continence.

Prior-Apprised Unsupervised Learning of Subpixel Curvilinear Features in Low Signal/Noise Images.

Many biophysical problems involve molecular and nanoscale targets moving next to a curvilinear track, e.g., a cytosolic cargo transported by motor proteins moving along a microtubule. For this type of problem, fluorescence imaging is usually the primary tool of choice. There is, however, an ∼20-fold mismatch between target-localization precision and track-imaging resolution such that questions requiring high-fidelity definition of the target's track remain inaccessible. On the other hand, if the contextual image of the tracks can be refined to a level comparable to that of the target, many intuitive yet mechanistically important issues can begin to be addressed. This work demonstrates that it is possible to statistically infer, to subpixel precision, curvilinear features in a low signal/noise image. This is achieved by a framework that consists of three stages: the Hessian-based feature enhancement, the subimage feature sampling and registration, and the statistical learning of the underlying curvilinear structure using a new, to our knowledge, method developed here for inferring the principal curves. In each stage, the descriptive prior information that the features come from curvilinear elements is explicitly taken into account. It is fully automated without user supervision, which is distinctly different from approaches that require user seeding or well-defined training data sets. Computer simulations of realistic images are used to investigate the performance of the framework and its implementation. The characterization results suggest that curvilinear features are refined to the same order of precision as that of the target and that the bootstrap confidence intervals from the analysis allow an estimate for the statistical bounds of the simulated "true" curve. Also shown are analyses of experimental images from three different microscopy modalities: two-photon laser-scanning microscopy, epifluorescence microscopy, and total internal reflection fluorescence microscopy. The practical application of this prior-apprised unsupervised learning framework as well as its potential outlook are discussed.

Unraveling the Mechanism of cyclo-N5- Production through Selective C-N Bond Cleavage of Arylpentazole with Ferrous Bisglycinate and m-Chloroperbenzonic Acid: A Theoretical Perspective.

Very recently, the bulk synthesis of cyclo-N5- from arylpentazole through the treatment with m-chloroperbenzonic acid (m-CPBA) and ferrous bisglycinate ([Fe(Gly)2]) (Zhang, C., et al. Science 2017, 355, 374) has greatly promoted the application of pentazolate anion as a novel high-performance energetic material. Yet the mechanism for this reaction is still unexplored. Herein we perform mechanistic studies on the selective C-N bond cleavage in arylpentazole by using density functional theory methods. The direct C-N bond activation by m-CPBA was computed to be kinetically inaccessible. Instead, the oxidation of [Fe(Gly)2] by m-CPBA is much favorable, which leads to the generation of a high-valent iron(IV)-oxo product. The Fe(IV)-oxo intermediate has been examined by UV-vis absorption spectra experiments and further verified by excited-state calculations. It is found that the Fe(IV)-oxo serves as the key intermediate for the C-N bond activation of arylpentazole and the cyclo-N5- generation. Our calculations clarified the key mechanistic details of the cyclo-N5- generation, and the factors that affect the production yield are further discussed.

Myokine/Adipokine Response to "Aerobic" Exercise: Is It Just a Matter of Exercise Load?

PURPOSE: Exercise health benefits are partly mediated by exertional changes in several myokines/adipokines. This study aimed to compare the acute response of some of these biomarkers to aerobic exercise performed at the intensity corresponding to the maximum fat oxidation rate (FATmax) or the "anaerobic" threshold (AT). METHODS: Following a cross-over, counterbalanced design, 14 healthy untrained men (23 ± 1 years) performed a 45-min exercise bout at their FATmax or AT intensity (been previously determined through incremental exercise tests). The concentration of interleukin (IL)-15, follistatin, myostatin, fibroblast-growth factor (FGF)-21, irisin, resistin, and omentin was measured at baseline and 0, 1, 3, 24, 48, and 72 h post-exercise. RESULTS: AT exercise was performed at a higher intensity (85 ± 8 vs. 52 ± 14% of maximal oxygen uptake [VO2 max], p < 0.001) and induced a higher energy expenditure (p < 0.001) than FATmax, whereas a greater fat oxidation was observed in the latter (p < 0.001). A higher peak response of FGF-21 (+90%, p < 0.01) and follistatin (+49%, p < 0.05) was found after AT-exercise, as well as a trend toward a higher peak level of omentin (+13%, p = 0.071) and a greater decrease in resistin (-16%, p = 0.073). CONCLUSION: Increasing exercise load (from FATmax to AT) results in a higher response of FGF-21, follistatin and omentin to aerobic exercise, with the subsequent potential cardiometabolic benefits. No effects were, however, observed on the remainder of biomarkers. Future research should address if manipulating other exercise variables (e.g., type, frequency) can promote a higher myokine/adipokine response.

Myokine Response to High-Intensity Interval vs. Resistance Exercise: An Individual Approach.

Purpose: This study aimed to compare the response to acute exercise of several myokines/hormones involved in metabolic function between two types of training sessions that are growing in popularity for their purported cardiometabolic benefits, high-intensity interval (HIIT) and resistance training (RT). Methods: Seventeen healthy, non-athletic men (23 ± 3 years) participated in this cross-over study. They randomly performed a HIIT [with short (HIIT1) or long (HIIT2) intervals] or a RT session. The concentration of fibroblast-growth factor (FGF) 21, follistatin, ghrelin, interleukin-15, irisin, myostatin, and peptide YY was measured at baseline and 0, 1, 3, 24, 48, and 72 h post-exercise. An individual approach was adopted to determine the rate of responsiveness to each specific cytokine and training mode. Results: A significant condition (session type) by time interaction (p = 0.004) effect was observed for FGF21, with RT eliciting a greater area under the curve (AUC) concentration than HIIT1 (p = 0.02). The AUC for follistatin was significantly greater after HIIT2 compared with RT (p = 0.02). Individual responsiveness to all session types ranged between 19 and 93% depending on the cytokine. However, most subjects (71-100%) responded positively for all cytokines (except for irisin, with only 53% of responders) after 1+ session type. Conclusion: Except for FGF21, our results show no overall differences in the myokine response to HIIT or RT. A considerable individual variability was observed, with some subjects responding to some but not other training session types. Notwithstanding, most responded to at least one training session. Thus, it is mostly the individual response of each subject rather than general recommendations on type of training session (i.e., RT vs. HIIT or HIIT subtypes) that must be taken into consideration for maximizing cardiometabolic benefits in the context of personalized exercise prescription.

Detection of Velocity and Diffusion Coefficient Change Points in Single-Particle Trajectories.

The position-time trajectory of a biological subject moving in a complex environment contains rich information about how it interacts with the local setting. Whether the subject be an animal or an intracellular endosomal vesicle, the two primary modes of biological locomotion are directional movement and random walk, respectively characterized by velocity and diffusion coefficient. This contribution introduces a method to quantitatively divide a single-particle trajectory into segments that exhibit changes in the diffusion coefficient, velocity, or both. With the determination of these two physical parameters given by the maximum likelihood estimators, the relative precisions are given as explicit functions of the number of data points and total trajectory time. The method is based on rigorous statistical tests and does not require any presumed kinetics scheme. Results of extensive characterizations, extensions to 2D and 3D trajectories, and applications to common scenarios are also discussed.

[Comparison of oncology outcomes and anal function among laparoscopic partial, subtotal and total intersphincteric resection for low rectal cancers].

OBJECTIVE: To compare the oncology outcomes and anal function among laparoscopic partial, subtotal and total intersphincteric resection(ISR) for low rectal cancers. METHODS: From June 2011 to February 2016, a total of 79 consecutive patients with low rectal cancers underwent laparoscopic ISR with hand-sewn coloanal anastomosis at our department. According to the distal tumor margin, partial ISR (internal sphincter resection at the dentate line) was used to treat tumors with distance <1 cm from the anal sphincter (n=28), subtotal ISR was adopted for the tumors locating between the dentate line and intersphincteric groove (n=34), and total ISR (resection at the dentate line) was applied in the treatment of intra-anal tumors (n=17). Anal function was evaluated by a standardized gastrointestinal questionnaire, Wexner incontinence score and Kirwan's classification. Metaphase oncological results and postoperative anal function were compared among three groups, and. RESULTS: Other than the distance of tumor low margin to dentate line (P=0.000) and serum CEA level (P=0.040), no significant differences were noted in baseline data among 3 groups (all P>0.05). The median follow up was 21(8-61) months. The 3-year disease-free survival rates in laparoscopic partial, subtotal and total ISR groups were 91.1%, 88.9%, 88.2% (P=0.901) and the 3-year local relapse-free survival rates were 91.1%, 72.9%, 80.2%(P=0.658), whose all differences were not significant. Thirty-eight patients who did not receive neoadjuvant chemoradiotherapy and underwent ileostomy closure for at least 24 months completed the evaluation of anal function, including 14 cases in partial group, 15 cases in subtotal group and 9 cases in total group. Of 38 patients, 73.7%(28/38) was classified as good function (Wexner incontinence score ≤10) and no patient adopted a colostomy because of severe fecal incontinence(Kirwan classification=grade 5). Furthermore, there were no significant differences in Wexner incontinence score and Kirwan classification among 3 groups (all P>0.05). However, patients with chronic anastomotic stoma stenosis showed worse anal function than those without stenosis [Wexner incontinence score: 18(9-20) vs 6(0-18), P=0.000; Kirwan grading: 3(2-4) vs. 2(1-4), P=0.002]. CONCLUSIONS: As the ultimate sphincter-saving technique, laparoscopic ISR can result in better oncologic outcomes and better anal function for patients with low rectal cancers. The different procedures of ISR may not affect the efficacy, but chronic anastomotic stoma stenosis deteriorates incontinence status.

[Treatment of complications after laparoscopic intersphincteric resection for low rectal cancer].

OBJECTIVE: To summarize the perioperative and postoperative complications follow laparoscopic intersphincteric resection (LapISR) in the treatment of low rectal cancer and their management. METHODS: An observational study was conducted in 73 consecutive patients who underwent LapISR for low rectal cancer between June 2011 and February 2016 in our hospital. The clinicopathological parameters, perioperative and postoperative complications, and clinical outcomes were collected from a prospectively maintained database. Perioperative and postoperative complications were defined as any complication occurring within or more than 3 months after the primary operation, respectively. RESULTS: Forty-nine(67.1%) cases were male and 24(32.9%) were female with a median age of 61(25 to 79) years. The median distance from distal tumor margin to anal verge was 4.0(1.0 to 5.5) cm. The median operative time was 195 (120 to 360) min, median intra operative blood loss was 100 (20 to 300) ml, median number of harvested lymph nodes was 14(3 to 31) per case. All the patients underwent preventive terminal ileum loop stoma. No conversion or hospital mortality was presented. The R0 resection rate was 98.6% with totally negative distal resection margin. A total of 34 complication episodes were recorded in 21(28.8%) patients during perioperative period, and among which 20.6%(7/34) was grade III(-IIII( according to Dindo system. Anastomosis-associated morbidity (16.4%,12/73) was the most common after LapISR, including mucosa ischemia in 9 cases(12.3%), stricture in 7 cases (9.6%, 4 cases secondary to mucosa necrosis receiving anal dilation), grade A fistula in 3 cases (4.1%) receiving conservative treatment and necrosis in 1 case (1.4%) receiving permanent stoma. After a median follow up of 21(3 to 60) months, postoperative complications were recorded in 12 patients (16.4%) with 16 episodes, including anastomotic stenosis (8.2%), rectum segmental stricture (5.5%), ileus (2.7%), partial anastomotic dehiscence (1.4%), anastomotic fistula (1.4%), rectovaginal fistula (1.4%) and mucosal prolapse (1.4%). These patients received corresponding treatments, such as endoscopic transanal resection, anal dilation, enema, purgative, permanent stoma, etc. according to the lesions. Six patients (8.2%) required re-operation intervention due to postoperative complications. CONCLUSION: Anastomosis-associated morbidity is the most common after LapISR in the treatment of low rectal cancer in perioperative and postoperative periods, which must be strictly managed with suitable methods.

Clinical and functional results of laparoscopic intersphincteric resection for ultralow rectal cancer: is there a distinction between the three types of hand-sewn colo-anal anastomosis?

PURPOSE: The purpose of this study is to compare the clinical and functional outcomes of three types of hand-sewn colo-anal anastomosis (CAA) after laparoscopic intersphincteric resection (Lap-ISR) for patients with ultralow rectal cancer. METHODS: A total of 79 consecutive patients treated by Lap-ISR for low-lying rectal cancer in an academic medical center from June 2011 to February 2016. According to the distal tumor margin and individualized anal length, the patients underwent three types of hand-sewn CAA including partial-ISR, subtotal-ISR, and total-ISR. RESULTS: Of the 79 patients, 35.4% required partial-ISR, 43% adopted subtotal-ISR, and 21.5% underwent total-ISR. R0 resection was achieved in 78 patients (98.7%). In addition to distal resection margin, there were no significant differences in clinicopathological parameters and postoperative complications between the three groups. The type of hand-sewn CAA did not influence the 3-year disease-free survival (DFS) or local relapse-free survival (LFS). At 24-months follow-up, in spite of higher incontinence scores in total-ISR group, there were not statistically significant differences in functional outcomes including Wexner score or Kirwan grade between the groups. Nevertheless, patients with chronic anastomotic stricture showed worse anal function than those without the complication. CONCLUSION: The type of hand-sewn CAA after Lap-ISR may not influence oncological and functional outcomes, but chronic stricture deteriorates continence status.

State-resolved dynamics study of the H + HS reaction on the 3A' and 3A″ states with time-dependent quantum wave packet method.

The quantum dynamics calculations of the H + HS (v = 0, j = 0) reaction on the 3A' and 3A″ potential energy surfaces (PESs) are performed using the reactant coordinate based time-dependent wave packet method. State-averaged and state-resolved results for both channels of the title reaction are presented in the 0.02-1.0 eV collision energy range and compared with those carried out with quasi-classical trajectory (QCT) method. Total integral cross sections (ICSs) for both channels are in excellent agreement with previous quantum mechanical (QM)-Coriolis coupling results while poorly agree with the QCT ICSs of the exchange channel, particularly near the threshold energy region. The product rotational distributions show that for the abstraction channel, the agreement between our QM and the QCT results improves with increasing collision energy. For the exchange channel, our calculations predict colder rotational distributions as compared to those obtained by QCT calculations. Although the QM total differential cross sections (DCSs) are in qualitatively good agreement with the QCT results, the two sets of the state-to-state DCSs with several peaks exhibit great divergences. The origin of the divergences are traced by analyzing the QM DCS for the H + HS (v = 0, j = 0) → H2 (v' = 0, j' = 0) + S reaction on the 3A″ PES at Ec = 1.0 eV. It is discovered that several groups of J partial waves are involved in the reaction and the shape of the DCS is greatly altered by quantum interferences between them.