A new model of Notch signalling: Control of Notch receptor cis-inhibition via Notch ligand dimers.

All tissue development and replenishment relies upon the breaking of symmetries leading to the morphological and operational differentiation of progenitor cells into more specialized cells. One of the main engines driving this process is the Notch signal transduction pathway, a ubiquitous signalling system found in the vast majority of metazoan cell types characterized to date. Broadly speaking, Notch receptor activity is governed by a balance between two processes: 1) intercellular Notch transactivation triggered via interactions between receptors and ligands expressed in neighbouring cells; 2) intracellular cis inhibition caused by ligands binding to receptors within the same cell. Additionally, recent reports have also unveiled evidence of cis activation. Whilst context-dependent Notch receptor clustering has been hypothesized, to date, Notch signalling has been assumed to involve an interplay between receptor and ligand monomers. In this study, we demonstrate biochemically, through a mutational analysis of DLL4, both in vitro and in tissue culture cells, that Notch ligands can efficiently self-associate. We found that the membrane proximal EGF-like repeat of DLL4 was necessary and sufficient to promote oligomerization/dimerization. Mechanistically, our experimental evidence supports the view that DLL4 ligand dimerization is specifically required for cis-inhibition of Notch receptor activity. To further substantiate these findings, we have adapted and extended existing ordinary differential equation-based models of Notch signalling to take account of the ligand dimerization-dependent cis-inhibition reported here. Our new model faithfully recapitulates our experimental data and improves predictions based upon published data. Collectively, our work favours a model in which net output following Notch receptor/ligand binding results from ligand monomer-driven Notch receptor transactivation (and cis activation) counterposed by ligand dimer-mediated cis-inhibition.

Manganese Local Environment Modulation via SiO4 Substitution to Boost Sodium Storage Performance of Na4 MnCr(PO4 )3.

Manganese-based Na superionic conductors (NASICONs) Na4 MnCr(PO4 )3 with three-electron reaction are attractive cathode materials for sodium-ion batteries. However, the irreversible distortion of Mn local structure leads to sluggish electrode kinetics, voltage hysteresis, and poor cycling stability. Here, SiO4 is introduced to substitute PO4 to modulate the local environment of Mn to activate the redox activity and stabilize the reversibility of Na4 MnCr(PO4 )2.9 (SiO4 )0.1 (NMCP-Si). A combined experimental and theoretical investigation have been undertaken to reveal the evolution of electronic structures and Na storage properties associated with SiO4 substitution. The NMCP-Si exhibits much-enhanced rate capability and cycling stability, being attributed to the unique Jahn-Teller distortion (Mn3+ ) that facilitates sodium de/insertion kinetics by optimizing the Na ion diffusion channels. This work addresses the challenge of stabilizing the structure of Mn-based NASICONs and represents a breakthrough in understanding how to improve the Na+ conductivity by regulating local structure.

Improving the ability of straw biochar to remediate Cd contaminated soil: KOH enhanced the modification of K3PO4 and urea on biochar.

In recent years, the improvement of soil cadmium (Cd) contamination remediation effect of biochar by modification has received wide attention. However, the effect of combined modification on biochar performance in soil Cd contamination remediation and the mechanism are still unclear. In this study, cotton straw biochar and maize straw biochar were co-modified by KOH (0, 3, 5 mol L-1), K3PO4, and urea. Then, two modified biochars with high Cd adsorption capacity were selected to test the soil Cd contamination remediation effect through a pot experiment. The results showed that the combined modification by using KOH, K3PO4, and urea significantly increased the specific surface area and nitrogen (N) and phosphorus (P) contents of biochar, providing more adsorption sites for Cd. Among the modified biochar, the cotton straw biochar modified with KOH (3 mol L-1), K3PO4, and urea (m3-CSB) had the highest adsorption capacity (111.25 mg g-1), which was 7.86 times that of cotton straw biochar (CSB). The m3-CSB for adsorption isotherm and kinetics of Cd conformed to the Langmuir model and Pseudo-second-order kinetic equation, respectively. In the pot experiment, under different exogenous Cd levels (0 (Cd0), 4 (Cd4), and 8 (Cd8) mg kg-1), m3-CSB treatment decreased soil available Cd content the most (51.68%-63.4%) compared with other biochar treatments. Besides, m3-CSB treatment significantly promoted the transformation of acid-soluble Cd to reducible, oxidizable, and residual Cd, reducing the bioavailability of Cd. At the Cd4 level, the application of m3-CSB significantly reduced cotton Cd uptake compared to CK, and the maximum reduction of Cd content in cotton fibers was as high as 81.95%. Therefore, cotton straw biochar modified with KOH (3 mol L-1), K3PO4, and urea has great potential in the remediation of soil Cd contamination.

Application of cotton straw biochar and compound Bacillus biofertilizer decrease the bioavailability of soil cd through impacting soil bacteria.

BACKGROUND: Cd seriously threatens soil environment, remedying Cd in farmland and clearing the response of soil environment to modifiers in Cd-contaminated soils is necessary. In this study, the effects of cotton straw biochar and compound Bacillus biofertilizer used as modifiers on the biochemical properties, enzyme activity, and microbial diversity in Cd-contaminated soils (1, 2, and 4 mg·kg-1) were investigated. RESULTS: The results showed that both cotton straw biochar and compound Bacillus biofertilizer could improve the soil chemical characteristics, including the increase of soil C/N ratio, electrical conductance (EC) and pH, and the most important decrease of soil available Cd content by 60.24% and 74.34%, respectively (P < 0.05). On the other hand, adding cotton straw biochar and compound Bacillus biofertilizer in Cd stressed soil also improved soil biological characteristics. Among them, cotton straw biochar mainly through increasing soil alkaline phosphatase activity and improve bacteria abundance, compound Bacillus biofertilizer by increasing soil invertase, alkaline phosphatase, catalase, and urease activity increased bacterial community diversity. On the whole, the decrease of soil available Cd was mainly caused by the increase of soil pH, C/N, urease and alkaline phosphatase activities, and the relative abundance of Acidobacteria and Proteobacteria. CONCLUSIONS: In summary, the applications of cotton straw biochar and compound Bacillus biofertilizer could decrease soil available Cd concentration, increase soil bacterial community diversity and functions metabolism, and reduce the damage of Cd stress, compared with cotton straw biochar, compound Bacillus biofertilizer was more effective in immobilizing Cd and improving soil environmental quality.

Cotton straw biochar and Bacillus compound biofertilizer decreased Cd migration in alkaline soil: Insights from relationship between soil key metabolites and key bacteria.

Cadmium (Cd) contamination greatly impacts soil health and ecological environment. In recent years, cotton straw biochar and Bacillus compound biofertilizer have been paid much attention in the remediation of Cd-contaminated soils. In this study, the effects of cotton straw biochar (3%, w/w) and Bacillus compound biofertilizer (1.5%, w/w) on the Cd fractions, Cd migration, bacterial community succession, and metabolites in the soils with different concentrations of Cd (1, 2, and 4 mg kg-1) were explored. The results showed that the relative abundance of Actinobacteriota, Acidobacteriota, Firmicutes, and Cyanobacteric and soil enzyme activities in Cd-contaminated soils decreased, and the soil metabolic pathways also changed compared with those in the control. After the application of cotton straw biochar and Bacillus compound biofertilizer, the soil available Cd concentration in Cd-contaminated soils decreased, and many exchangeable and carbonate-bound Cd were transformed into residual Cd, which decreased the bioavailability of Cd in the soil and the accumulation of Cd in cotton organs. In addition, the application of cotton straw biochar and Bacillus compound biofertilizer improved the activity of soil enzymes and the abundance of dominant bacteria and stimulated Verrucomicrobiota, Methylomirabilota, and Cyanobacteria to secrete organic acids and amino acid compounds, which decreased the toxicity of Cd. Besides, compared with cotton straw biochar, Bacillus compound biofertilizer was more effective in immobilizing Cd and improving soil environment. This study provides guidance for the remediation of Cd-contaminated alkaline soil, and makes contributions to the soil health and sustainable development.

Clinical efficacy of intravesical gemcitabine combined with ubenimex in patients with non-muscle-invasive bladder carcinoma after transurethral resection of bladder tumor.

Objectives: To evaluate the clinical value of intravesical gemcitabine combined with immunotherapy in patients with non-muscle-invasive bladder carcinoma (NMIBC) after transurethral resection of bladder tumor (TURBT). Methods: Eighty patients with non-muscle-invasive urothelial carcinoma treated in Baoding No.1 Hospital from November 2016 to November 2019 were randomly divided into two groups, with 40 patients in each group. Both groups underwent TURBT. After surgery, the research group was treated with intravesical chemotherapy using gemcitabine combined with ubenimex, while the control group was given 40 mg pirarubicin by intravesical instillation. Postoperative condition was evaluated by cystoscopy every three months in both groups. The recurrence six months, one year and two years after treatment, the incidence of lower urinary tract symptoms such as dysuria, hematuria and frequent urination, general adverse drug reactions such as rashes, liver function damage and gastrointestinal reaction, as well as the changes in CD3+, CD4+, CD8+ and CD4+/CD8+ T lymphocyte subsets before and after treatment were comparatively analyzed between the two groups. Results: The recurrence rate showed no statistical significance between the two groups 6 months after treatment (p=0.17), but significant differences one year (p=0.04) and two years (p=0.03) after treatment, which were significantly lower in the research group than the control group. The incidence of adverse drug reactions was 22.5% in the research group and 7.5% in the control group, without significant difference (p=0.36). The incidence of lower urinary tract symptoms was 32.5% and 55%, respectively, in the research group and the control group. The incidence of lower urinary tract symptoms in the research group was significantly lower compared with the control group, with a statistically significant difference (p=0.04). After treatment, CD3+, CD4+ and CD4+/CD8+ levels in the research group increased significantly than those in the control group, with statistically significant differences (CD3+, p=0.01; CD4+, p=0.00; CD4+/CD8+, p=0.00). Conclusions: For NMIBC patients receiving bladder-preserving surgery, intravesical gemcitabine combined with immunotherapy can reduce the recurrence rate, relieve lower urinary tract symptoms, increase the tolerance of patients to intravesical chemotherapy and significantly improve the function of T lymphocytes, without obvious increase in adverse drug reactions. Therefore, it is safe and effective, and has certain clinical value.

Benchmarking Phases of Ruthenium Dichalcogenides for Electrocatalysis of Hydrogen Evolution: Theoretical and Experimental Insights.

The hydrogen evolution reaction (HER) is a significant cathode step in electrochemical devices, especially in water splitting, but developing efficient HER catalysts remains a great challenge. Herein, comprehensive density functional theory calculations are presented to explore the intrinsic HER behaviors of a series of ruthenium dichalcogenide crystals (RuX2 , X = S, Se, Te). In addition, a simple and easily scaled production strategy is proposed to synthesize RuX2 nanoparticles uniformly deposited on carbon nanotubes. Consistent with theoretical predictions, the RuX2 catalysts exhibit impressive HER catalytic behavior. In particular, marcasite-type RuTe2 (RuTe2 -M) achieves Pt-like activity (35.7 mV at 10 mA cm-2 ) in an acidic electrolyte, and pyrite-type RuSe2 presents outstanding HER performance in an alkaline media (29.5 mV at 10 mA cm-2 ), even superior to that of commercial Pt/C. More importantly, a RuTe2 -M-based proton exchange membrane (PEM) electrolyzer and a RuSe2 -based anion exchange membrane (AEM) electrolyzer are also carefully assembled, and their outstanding single-cell performance points to them being efficient cathode candidates for use in hydrogen production. This work makes a significant contribution to the exploration of a new class of transition metal dichalcogenides with remarkable activity toward water electrolysis.

COVID-19-induced layoff, survivors' COVID-19-related stress and performance in hospitality industry: The moderating role of social support.

The COVID-19 pandemic has hit the hospitality industry hard globally, resulting in millions of employees being laid off. Drawing upon the conservation of resources theory, this study aims to empirically examine how and when COVID-19-induced layoff influences employees' in-role and extra-role performance in the hospitality industry. We tested this model by using field data collected from 302 employees and their supervisors in China across two waves. Results revealed that COVID-19-induced layoff increases survivors' COVID-19-related stress, which in turn leads to decreased in-role and extra-role performance. The strength of these indirect effects is mitigated by perceived family support against COVID-19. Unexpectedly, perceived organizational support against COVID-19 intensifies these indirect effects. The theoretical and practical implications of this study are further discussed.

Do emotional labour strategies influence emotional exhaustion and professional identity or vice versa? Evidence from new nurses.

AIMS: The aim was to examine the reciprocal relationships of emotional labour strategies with emotional exhaustion and professional identity. DESIGN: This study adopted a four-wave cross-lagged panel design. METHODS: Survey data were collected in 2018 from a sample of 171 newly hired nurses from 58 hospitals in 11 provinces of China. Nurses' emotional labour (i.e., deep acting and surface acting), emotional exhaustion and professional identity were repeatedly measured. Cross-lagged panel analyses were conducted to examine the reciprocal relationships we hypothesized. RESULTS: We found that emotional exhaustion was positively related to surface acting (but not vice versa); deep acting was negatively related to emotional exhaustion (but not vice versa); professional identity was positively related to deep acting (but not vice versa). CONCLUSION: Our findings suggest that deep acting and professional identity may decrease the level of emotional exhaustion, whereas emotionally exhausted nurses are more likely to employ surface acting strategies. IMPACT: This research finding will have an impact on the nursing management. Healthcare managers may consider workshops or training and development programs that promote nurses' professional identify to promote nurses' use of deep acting and consequently reduce their level of emotional exhaustion, which has been associated with a variety of negative consequences, such as low quality of patient service, high medical accidents, and turnover rate.

Uniportal Thoracoscopic Wedge Resection of Lung Nodules: Paravertebral Blocks Are Better Than Intercostal Blocks.

Background. Regional analgesia for tubeless, uniport, thoracoscopic wedge resection of benign peripheral nodules is generally performed by intercostal nerve block (INB). We examined the effectiveness of thoracic paravertebral block (PVB), in comparison to the traditional intercostal blocks, for the procedure. Methods. Between July 2016 and December 2016, 20 consecutive patients with solitary benign peripheral lung nodules underwent tubeless uniport thoracoscopic wedge resection using thoracic PVB (PVB group). The clinical outcomes were compared with those of 20 other consecutive patients who underwent the same procedure under the conventional INB, between January 2016 and July 2016 (INB group). In both groups, the procedures were performed without endotracheal intubation, urinary catheterization, or chest tube drainage. Results. The clinical data of patients in both groups were comparable in terms of demographic and baseline characteristics, operative and anesthetic characteristics, puncture-related complications, and postoperative anesthetic adverse events. No puncture-related complications occurred during the perioperative period in either group. The threshold values for mechanical pain at postoperative hours 4 and 8 were significantly higher in the PVB group than in the INB group. Furthermore, the incidence of nausea or vomiting in the PVB group was significantly less than that in the INB group. None of the patients required reintervention or readmission to our hospital. Conclusions. Tubeless uniportal thoracoscopic wedge resection for solitary benign peripheral lung nodules using thoracic PVB for regional analgesia is a feasible and safe procedure. Moreover, we found that thoracic PVB is less painful than INB.

A Spectroscopic Study of Electrochemical Nitrogen and Nitrate Reduction on Rhodium Surfaces.

Rh is a promising electrocatalyst for the nitrogen reduction reaction (NRR) given its suitable nitrogen-adsorption energy and low overpotential. However, the NRR pathway on Rh surfaces remains unknown. In this study, we employ surface-enhanced infrared-absorption spectroscopy (SEIRAS) and differential electrochemical mass spectrometry (DEMS) to study the reaction mechanism of NRR on Rh. N2 Hx (0≤x≤2) is detected with a N=N stretching mode at ≈2020 cm-1 by SEIRAS and a signal at m/z=29 by DEMS. A new two-step reaction pathway on Rh surfaces is proposed that involves an electrochemical process with a two-electron transfer to form N2 H2 and its subsequent decomposition in the electrolyte producing NH3 . Our results also indicate that nitrate reduction and the NRR share the same reaction intermediate N2 Hx .

Exosomal circRNAs: biogenesis, effect and application in human diseases.

Exosomes have emerged as critical mediators of intercellular communication, both locally and systemically, by regulating a diverse range of biological processes between cells. Circular RNA (circRNA) is a novel member of endogenous noncoding RNAs with widespread distribution and diverse cellular functions. Recently, circular RNAs have been identified for their enrichment and stability in exosomes. In this review, we outline the origin, biogenesis and function of exosomal circRNAs as well as their roles in various diseases. Although their precise roles and mechanisms of gene regulation remain largely elusive, exosomal circRNAs have potential applications as disease biomarkers and novel therapeutic targets.

Effects of exosomes on pre-metastatic niche formation in tumors.

A pre-metastatic niche is a microenvironment prepared for the colonization of circulating tumor cells in specific organs. Exosomes are extracellular vesicles with a variety of biological functions. Exosomes play an irreplaceable role in the development of pre-metastatic niches, and mainly function as communication medium. In this review, we analyzed the effects of exosomes on pre-metastatic niches from various perspectives, including inflammation, immune response, angiogenesis, organotropism, matrix remodeling and biomarker expression. In particular, exosomes express programmed death ligand 1 (PD-L1) and cause the immune escape of tumor cells. The immunomodulatory effects of exosomes and their potential in liquid diagnosis have drawn our attention. The potential value of exosomes and pre-metastatic niches will be realized in the field of immunity therapy.

Resveratrol attenuates cerebral ischaemia reperfusion injury via modulating mitochondrial dynamics homeostasis and activating AMPK-Mfn1 pathway.

The pathogenesis of cerebral ischaemia reperfusion injury (IRI) has not been fully described. Accordingly, there is little effective drug available for the treatment of cerebral IRI. The aim of our study was to explore the exact role played by Mfn1-mediated mitochondrial protection in cerebral IRI and evaluate the beneficial action of resveratrol on reperfused brain. Our study demonstrated that hypoxia-reoxygenation (HR) injury caused N2a cell apoptosis and this process was highly affected by mitochondrial dysfunction. Decreased mitochondrial membrane potential, increased mitochondrial oxidative stress, and an activated mitochondrial apoptosis pathway were noted in HR-treated N2a cells. Interestingly, resveratrol treatment could attenuate N2a cell apoptosis via sustaining mitochondrial homeostasis. Further, we found that resveratrol modulated mitochondrial performance via activating the Mfn1-related mitochondrial protective system. Knockdown of Mfn1 could abolish the beneficial effects of resveratrol on HR-treated N2a cells. Besides, we also report that resveratrol regulated Mfn1 expression via the AMPK pathway; inhibition of AMPK pathway also neutralized the anti-apoptotic effect of resveratrol on N2a cells in the setting of cerebral IRI. Taken together our results show that mitochondrial damage is closely associated with the progression of cerebral IRI. In addition we also demonstrate the protective action played by resveratrol on reperfused brain and show that this effect is achieved via activating the AMPK-Mfn1 pathway.

Mechanical Properties and Corrosion Resistance of NbTiAlSiZrNx High-Entropy Films Prepared by RF Magnetron Sputtering.

In this study, we designed and fabricated NbTiAlSiZrNx high-entropy alloy (HEA) films. The parameters of the radio frequency (RF) pulse magnetron sputtering process were fixed to maintain the N2 flux ratio at 0%, 10%, 20%, 30%, 40%, and 50%. Subsequently, NbTiAlSiZrNx HEA films were deposited on the 304 stainless steel (SS) substrate. With an increasing N2 flow rate, the film deposited at a RN of 50% had the highest hardness (12.4 GPa), the highest modulus (169 GPa), a small roughness, and a beautiful color. The thicknesses of the films were gradually reduced from 298.8 nm to 200 nm, and all the thin films were of amorphous structure. The electrochemical corrosion resistance of the film in a 0.5 mol/L H2SO4 solution at room temperature was studied and the characteristics changed. The HEA films prepared at N2 flow rates of 10% and 30% were more prone to corrosion than 304 SS, but the corrosion rate was lower than that of 304 SS. NbTiAlSiZrNx HEA films prepared at N2 flow rates of 20%, 40%, and 50% were more corrosion-resistant than 304 SS. In addition, the passivation stability of the NbTiAlSiZrNx HEA was worse than that of 304 SS. Altogether, these results show that pitting corrosion occurred on NbTiAlSiZrNx HEA films.

A Spectroscopic Study on the Nitrogen Electrochemical Reduction Reaction on Gold and Platinum Surfaces.

The electrochemical reduction of nitrogen to ammonia on Au-based catalysts showed a reasonably high Coulombic efficiency. The pathway of this promising reaction, however, is not clear partially due to the lack of information on reaction intermediates. Herein, surface-enhanced infrared absorption spectroscopy (SEIRAS) was employed to study the reaction mechanisms of nitrogen reduction on an Au thin film for the first time. During the nitrogen reduction, the N2Hy species was detected with bands at 1453 (H-N-H bending), 1298 (-NH2 wagging), and 1109 cm-1 (N-N stretching) at potentials below 0 V against reversible hydrogen electrode. This result indicates that the nitrogen reduction reaction on Au surfaces follows an associative mechanism, and the N≡N bond in N2 tends to break simultaneously with the hydrogen addition. By comparison, no absorption band associated with N was observed on Pt surfaces under the same reaction condition. This result is consistent with the low efficiency of nitrogen reduction on Pt due to the much faster kinetics of hydrogen evolution reaction.

Tumor Growth Assessment by Computed Tomography Perfusion Imaging (CTPI), Perfusion-Weighted Imaging (PWI), and Diffusion-Weighted Imaging (DWI) in a Rabbit Pleural Squamous Cell Carcinoma VX2-Implanted Model.

BACKGROUND Computed tomography perfusion imaging (CTPI) and perfusion-weighted imaging (PWI) are non-invasive technologies that can quantify tumor vascularity and blood flow. This study explored the blood flow information, tumor cell viability, and hydrothoraces in a rabbit pleural VX2-implanted model through use of CTPI, PWI, and DWI. MATERIAL AND METHODS A pleural VX2-implanted model was established in 58 New Zealand white rabbits. CTPI, PWI, and DWI were applied with a 16-slice spiral CT and an Archival 1.5 T dual-gradient MRI. RESULTS Compared with muscle tissue, PV, PEI, and BV of parietal and visceral pleural tumor implantation rabbits showed significant differences. The t values of PV, PEI, and BV between parietal and visceral pleura were 2.08, 2.29, and 2.88, respectively. Compared with muscle tissue, WIR, WOR, and MAXR of parietal and visceral pleural tumor implantation rabbits showed significant differences. In parietal pleural tumor implantation rabbits, the section surface of lesion tissues was 5.2±2.7 cm². Hydrothorax appeared 6.0±2.0 days after tumor implantation. The mean value of ADC was 1.5±0.6. In visceral pleural tumor implantation rabbits, the section surface of lesion tissues was 1.6±0.8 cm². Hydrothorax appeared 7.0±3.0 days after tumor implantation. The mean value of ADC was 1.4±0.5. The t values of the above 3 indices for the parietal and visceral pleura were 1.85, 1.83, and 1.76, respectively (P<0.05). CONCLUSIONS The combined application of CTPI, PWI, and DWI accurately and visually reflects the blood perfusion of tumor tissues and quantitatively analyzes blood flow information and the mechanism underlying hydrothorax generation in tumor tissues.

Imatinib therapy after resection of high-risk gastrointestinal stromal tumors in Chinese patients: a median follow-up of 48 months.

PURPOSE: Adjuvant imatinib can be given for gastrointestinal stromal tumors (GISTs), but adequate risk stratification is necessary to select patients who will benefit from this therapy. We aimed to investigate the treatment methods and prognostic factors of high risk GISTs. METHODS: This retrospective study included 108 patients who underwent tumor resection for high-risk GISTs between January 2003 and February 2017. The patients were divided into two groups: a group of patients received postoperative imatinib adjuvant therapy (Adjuvant therapy group), and the other group was not treated with imatinib until they were found to have disease progression (Followup observation group). The progression-free survival (PFS) and overall survival (OS) were compared between the two groups, and the risk factors of prognosis were analyzed by Cox regression model. RESULTS: The median PFS was 45 months (range 23-67). The 1-, 3-, and 5-year PFS was 88.6, 70.4 and 59.0%, respectively. The PFS in the adjuvant therapy group was longer than in the follow-up observation group (p<0.001). The median OS was 117 months (range 93-141). The 1-, 3-, and 5-year OS was 97.0, 87.7 and 77.4%, respectively. There was no difference in OS between the two groups (p=0.737). Intra-operative tumor integrity (p=0.003) and postoperative adjuvant treatment (p<0.001) were independent prognostic factors of PFS. R0 resection (p=0.019) and low mitotic count (≤5/50 HPF) (p=0.031) were independent prognostic factors of OS. CONCLUSIONS: Avoiding intra-operative tumor rupture and administering postoperative adjuvant imatinib treatment improved PFS in patients with high-risk GISTs. Low mitotic count and R0 resection were associated with better survival.

[Effects of increased body mass index on immediate clinical efficacy of radical gastrectomy].

OBJECTIVE: To explore the effects of increased body mass index (BMI) on immediate clinical efficacy of radical gastrectomy in patients with gastric cancer. METHODS: The data of 258 patients undergoing radical gastrectomy were collected retrospectively from January 2009 to January 2013. They were grouped by BMI into obese (BMI ≥ 25 kg/m², n = 118) and non-obese (BMI < 25 kg/m², n = 140) groups. And their intra and post-operative findings and survivals were compared between two groups. Follow-ups until January 2014 were conducted by outpatient visits, mail and telephone. SPSS 17.0 software was used for statistical analysis. RESULTS: For obese and non-obese groups, operative durations were (208.6 ± 60.9), (178.1 ± 62.5) min and number of lymph node dissection (23.4 ± 8.3), (29.8 ± 12.2) pieces respectively. And the difference was statistically significant (P < 0.05). And blood loss, overall incidence of postoperative complications, the number of metastatic lymph node dissection were (272.4 ± 128.8) ml, 30.5% (36/118), (7.9 ± 8.8) pieces and (260.8 ± 160.4) ml, 24.3% (34/140), (8.6 ± 10.2) pieces respectively. And the differences were not statistically significant (P > 0.05). The median follow-up period was 23 months. And the difference of cumulative survival was not statistically significant (χ² = 1.199, P = 0.274). CONCLUSIONS: Obesity is not an independent prognostic foactor for gastric cancer. But its related complications should be actively handled preoperatively. Intraoperative procedures are strictly performed. And postoperative nutritional supports are needed to lower the incidence of complications and imporve the prognosis.

Role of MR-DWI and MR-PWI in the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbits.

OBJECTIVE: To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging (MR-DWI) and magnetic resonance perfusion weighted imaging (MR-PWI), and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages. METHODS: A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine (Philips, Netherland). MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MR-DWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient (ADC) values; whereas MR-PWI was used for the measurement of wash in rate (WIR), wash out rate (WOR), and maximum enhancement rate (MER). The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 cGy to yield a total dosage of 5,000 cGy. RESULTS: THE ADC PARAMETERS IN THE REGION OF INTEREST ON DWI WERE AS FOLLOWS: on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group (P>0.05). During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137 (P>0.05). During weeks 1-2, the t values were 1.731 and 1.736 (P<0.05). During weeks 2-3, the t values were 1.742 and 1.749 (P<0.05). During weeks 3-4, the t values were 2.050 and 2.127 (P<0.05). During weeks 4-5, the t values were 2.764 and 2.985 (P<0.05). The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy (5,000 cGy), the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group (P>0.05); in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51 (P>0.05). During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931 (P<0.05); in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137 (P<0.05). During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057 (P<0.05). During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154 (P<0.05). During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951 (P<0.05). During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 3.45, 3.246, and 3.614 (P<0.05). After the radiotherapy (500 cGy), the tumors shrank on the T1WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value. CONCLUSIONS: MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung.