Control of Zeolite Local Polarity toward Efficient Xenon/Krypton Separation

The inherent inertness and striking physicochemical similarities of krypton and xenon pose significant challenges to their separation. Reported herein is the efficient xenon capture and xenon/krypton adsorptive separation by transition metal-free zeolites under ambient conditions. The polarized environment of zeolite, denoted as local polarity, can be tuned by changing the topology, framework composition, and counter-cations, which in turn correlates with the guest-host interaction and separation performance. Chabazite zeolite with a framework Si/Al ratio of 2.5 and Ca2+ as the counter-cations, namely, Ca-CHA-2.5, is developed as a state-of-the-art zeolite adsorbent, showing remarkable performance, i.e., high dynamic xenon uptake, high xenon/krypton separation selectivity, and good recyclability, in the adsorptive separation of the xenon/krypton mixture. Grand Canonical Monte Carlo simulation reveals that extraframework Ca2+ cations act as the primary binding sites for xenon and can stabilize xenon molecules together with the chabazite framework, whereas krypton molecules are stabilized by weak guest-host interaction with the zeolite framework.

[The safety and efficacy of prophylactic hyperthermic intraperitoneal chemotherapy for elderly patients with locally advanced gastric cancer: a propensity score matching analysis]

Objective: To evaluate the safety and efficacy of prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) on elderly patients diagnosed with locally advanced gastric cancer based on a propensity score matching analysis. Methods: Clinical data of elderly patients with locally advanced gastric cancer who underwent radical gastrectomy in Beijing Hospital from January 2017 to December 2021 were retrospectively collected. According to whether HIPEC was used, the patients were divided into HIPEC group (radical gastrectomy combined with HIPEC) and control group (radical gastrectomy alone), and 29 patients in HIPEC group and 122 patients in control group. After 1∶1 matching of PSM, there were 28 patients in each group. The clinicopathological data, surgical data, postoperative recovery and long-term survival of the two groups were compared and analyzed. Results: Before PSM, the mean age in the HIPEC group was (70.7±4.0) years, and in the control group was (73.1±5.8) years (P=0.011). After PSM, the mean age in the HIPEC group was (70.9±3.9) years, and it was (71.8±5.4) years in the control group (P=0.739). Before PSM, the incidence of postoperative complications was 20.7% (6 cases) in the HIPEC group and 26.2% (32 cases) in the control group (P=0.639). After PSM, the incidence of postoperative complications was 21.4% (6 cases) in the HIPEC group and 14.3% (4 cases) in the control group (P=0.730). Before PSM, the mean duration of hospitalization after radical gastrectomy was (13.6±7.6) days in HIPEC group and (16.2±13.0) days in control group, respectively (P=0.312). After PSM, the mean duration of hospitalization after radical gastrectomy was (13.7±7.8) days in HIPEC group and (15.4±9.7) days in control group, respectively (P=0.479). Before PSM, the 1-and 3-year overall survival rates of the HIPEC group were 88.2% and 69.7%, and 88.0% and 66.1% for control group, respectively, with no statistical difference between the two groups in overall survival (P=0.499). After PSM, the 1-and 3-year overall survival rates of the HIPEC group were 86.8% and 69.7%, and 93.1% and 67.5% for control group, respectively, with no statistical difference between the two groups in overall survival (P=0.425). Before PSM, the 1-and 3-year disease-free survival rates of the HIPEC group were 88.2% and 67.1%, and 87.8% and 64.3% for control group, respectively, with no statistical difference between the two groups in disease-free survival (P=0.863). After PSM, the 1-and 3-year disease-free survival rates of the HIPEC group were 88.2% and 62.8%, and 93.7% and 64.7% for control group, respectively, with no statistical difference between the two groups in disease-free survival (P=0.804). Conclusions: Radical surgery combined with HIPEC for elderly patients with gastric cancer does not increase postoperative complications and postoperative recovery time. However, there was no significant difference in overall survival and disease-specific survival between the two groups.

Zeolite-encaged mononuclear copper centers catalyze CO2 selective hydrogenation to methanol

The selective hydrogenation of CO2 to methanol by renewable hydrogen source represents an attractive route for CO2 recycling and is carbon neutral. Stable catalysts with high activity and methanol selectivity are being vigorously pursued, and current debates on the active site and reaction pathway need to be clarified. Here, we report a design of faujasite-encaged mononuclear Cu centers, namely Cu@FAU, for this challenging reaction. Stable methanol space-time-yield (STY) of 12.8 mmol gcat-1 h-1 and methanol selectivity of 89.5% are simultaneously achieved at a relatively low reaction temperature of 513 K, making Cu@FAU a potential methanol synthesis catalyst from CO2 hydrogenation. With zeolite-encaged mononuclear Cu centers as the destined active sites, the unique reaction pathway of stepwise CO2 hydrogenation over Cu@FAU is illustrated. This work provides a clear example of catalytic reaction with explicit structure-activity relationship and highlights the power of zeolite catalysis in complex chemical transformations.

Facile synthesis of aluminosilicate zeolites with STT, CHA and MWW topology structures

Efficient synthesis of zeolites with different topologies is of great significance for both fundamental research and industrial application. Herein, the SSZ-23 zeolite, an odd zeolite containing 7-membered ring (7-MR) and 9-MR channels, has been synthesized under fluorine-free conditions via the route of pre-aging and pH regulation. By this novel synthesis route, the crystallization time can be significantly shortened to 3 days, nearly half as that by the conventional route in fluoride media. The pH value of the aging gel, i.e., the basicity, is found to play a key role in the synthesis, as SSZ-13 and SSZ-25 zeolites can be synthesized simply by changing the basicity of the same aging gel. Characterization results indicate that decreasing the basicity can promote the condensation between Si and Si/Al species and thus increase the framework density of the resulting zeolites. Finally, the dimethyl ether (DME) carbonylation reaction is employed to evaluate the catalytic properties of the above three zeolites with an identical chemical composition, and to reveal the unique confinement effect in various zeolite topologies.

[Analysis of prognosis and related factors in oldest-old patients with left-side or right-side colon cancer after hemicolectomy]

Objective: This study aimed to explore the difference of prognosis in oldest-old colon cancer patients between the left-side and right-side hemicolectomy. Methods: A total of 238 oldest-old (≥75 years old) colon cancer patients who received surgical treatment in Gastrointestinal Surgery Department of Beijing Hospital from December 2010 to December 2020 were retrospectively collected. They were divided into right-side hemicolectomy (RCC) group (130 cases) and left-side hemicolectomy (LCC) group (108 cases) by surgical methods. The difference in postoperative short-term complications and long-term prognosis was compared between the two groups, and the related factors of postoperative death was analyzed using multivariate Cox regression model. Results: The age of 238 oldest-old patients with colon cancer ranged from 75 to 93 years old (80.5±3.7). There were 128 males and 110 females. The ages of patients in the LCC group and RCC group were (80.4±3.7) and (80.6±3.7) years old (P=0.699), respectively. There was no significant difference in gender, body mass index (BMI) and co-existing chronic diseases between two groups (P>0.05). The proportion of the duration of surgery exceeding 170 min in the LCC group was significantly higher than that in the RCC group (56.5% vs 43.1%, P=0.039). The incidence of postoperative short-term complications in RCC group was slightly higher than LCC group (P>0.05), and there was no significant difference in overall survival (OS), tumor-specific survival (CSS) and disease-free survival (DFS) between two groups. However, the two groups had different prognostic risk factors, pathological Ⅳ stage (HR=28.970,95%CI:1.768-474.813,P=0.018), intraoperative bleeding (HR=2.297,95%CI:1.351-3.907,P=0.002) and cancer nodules (HR=2.044,95%CI:1.047-3.989,P=0.036) were independent prognostic risk factors in LCC group. Underweight (HR=0.428,95%CI:0.192-0.955,P=0.038), overweight(HR=0.316,95%CI:0.125-0.800,P=0.015),obesity (HR=0.211,95%CI:0.067-0.658,P=0.007), lymph node metastasis (HR=2.682,95%CI:1.497-4.807,P=0.001), tumor nodule (HR=2.507,95%CI:1.301-4.831,P=0.027) and postoperative length of stay of 9 days (HR=1.829,95%CI:1.070-3.128,P=0.006) were independent risk factors for poor prognosis in RCC group. Conclusions: The duration of surgery of oldest-old colon cancer patients in the LCC group was longer than that in the RCC group. However, there was no significant difference in the incidence of postoperative complications between the two groups. High pathological stage, more intraoperative bleeding and cancer nodules were independent prognostic risk factors in the LCC group. Abnormal BMI, lymph node metastasis, cancer nodules and postoperative length of stay were independent risk factors for poor prognosis in the RCC group.

Stable and Uniform Extraframework Cations in Faujasite Zeolites

Extraframework transition metal ions (TMIs) in zeolites can serve as active sites for adsorption and catalysis. However, due to the complexity and mobility of extraframework cation sites, their applications are significantly limited and the structure-performance relationship is poorly understood. In this Perspective, stable and uniform TMIs in zeolites are exemplified and their characteristics are discussed. A series of TMIs can be introduced to specific cation sites of faujasite via a ligand-protected in situ synthesis route to construct uniform TMIs in the zeolite matrix, namely, TMI@FAU (TMI= Co, Ni, Cu, Rh, and Pt). Coordinatively unsaturated TMIs within faujasite are active for small-molecule adsorption and activation, and therefore, TMI@FAU zeolites show unique properties in adsorption and catalysis. TMI@FAU zeolites appear to be ideal model systems, and the well-defined structure of TMI@FAU greatly facilitates the mechanism studies by spectroscopic investigations and theoretical simulations.

Interaction of sleep duration and depression on cardiovascular disease: a retrospective cohort study

Background

To assess the interaction of sleep duration and depression on the risk of cardiovascular disease (CVD).

Methods

A total of 13,488 eligible participants were enrolled in this retrospective cohort study eventually. Baseline characteristics were extracted from the China Health and Retirement Longitudinal Study (CHARLS) database, including age, sex, diabetes, high-density lipoprotein (HDL), blood glucose (GLU), glycosylated hemoglobin (GHB) etc. Univariate and multivariate negative binomial regression models were carried out to assess the statistical correlation of sleep duration and depression on CVD separately. Additionally, multivariate negative binomial regression model was used to estimate the interaction of sleep duration and depression on CVD risk.

Results

After adjusting for age, sex, educational background, hypertension, diabetes, dyslipidemia, the use of hypnotics, disability, nap, drinking, deposit, sleep disturbance, HDL, triglyceride, total cholesterol, GLU and GHB, the risk of CVD in participants with the short sleep duration was increased in comparison with the normal sleep duration [relative risk (RR)=1.02, 95% confidence interval (CI):1.01-1.03]; compared to the participants with non-depression, participants suffered from depression had an increased risk of CVD (RR=1.05, 95%CI:1.04-1.06). Additionally, the result also suggested that the interaction between short sleep duration and depression on the risk of CVD was statistically significant in these patients with diabetes and was a multiplicative interaction.

Conclusion

An interaction between short sleep duration and depression in relation to an increased risk of CVD among Chinese middle-aged and elderly individuals was noticed, which may provide a reference that people with diabetes should focus on their sleep duration and the occurrence of depression, and coexisting short sleep duration and depression may expose them to a higher risk of CVD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14143-3.

[A descriptive analysis of tea consumption in adult twins in China]

Objective: To describe the distribution characteristics of tea consumption in adult twins recruited in the Chinese National Twin Registry (CNTR) and provide clues to genetic and environmental influences on tea consumption. Methods: Enrolled in CNTR during 2010-2018, 25 264 twin pairs aged 18 years and above were included in subsequent analysis. Random effect models were used to estimate tea consumption in the population and regional distribution characteristics. The concordance rate of the behavior and difference in consumption volume of tea within pairs were also described. Results: The mean age of all subjects was (35.38±12.45) years old. The weekly tea consumers accounted for 17.0%, with an average tea consumption of (3.36±2.44) cups per day. The proportion of weekly tea consumers was higher among males, 50-59 years old, southern, urban, educated, and the first-born in the twin pair (P<0.05), and lower among unmarried individuals (P<0.001). Within-pair analysis showed that the concordance rate of tea consumption of monozygotic (MZ) twins was higher than that of dizygotic (DZ) twins and the overall heritability of tea consumption was 13.45% (11.38%-15.51%). Stratified by the characteristics mentioned above, only in males, the concordance rate of MZ showed a tendency to be greater than that of DZ (all P<0.05). The differences in consumption volume of tea within twin pairs were minor in MZ among males (P<0.05), while the differences were not significant in female twins. Conclusion: There were discrepancies in the distribution of tea consumption among twins of different demographic and regional characteristics. Tea consumption was mainly influenced by environmental factors and slightly influenced by genetic factors. The size of genetic factors varied with gender, age, and region, and gender was a potential modified factor.

[A descriptive analysis on coronary heart disease in adult twins in China]

Objective: To describe the distribution characteristics of coronary heart disease in adult twins recruited from Chinese Twin Registry (CNTR), and provide clues and evidence for the effect of genetic and environmental influences on coronary heart disease. Methods: By using the data of CNTR during 2010-2018, a total of 34 583 twin pairs aged ≥18 years who completed questionnaire survey and had related information were included in the current study to analyze the population and area distribution characteristics of coronary heart disease. Random effect models were used to compare the differences between groups. The concordane rate of coronary heart disease were calculated respectively in monozygotic (MZ) twin pairs and dizygotic (DZ) twin pairs to estimate the heritability. Results: The twin pairs included in this analysis were aged (34.2±12.4) years. The overall prevalence rate of coronary heart disease in twin pairs was 0.7%. Twin pairs who were women, older, obese and lived in northern China had higher prevalence of coronary heart disease (P<0.05). Intra-pair analysis in the same-sex twin pairs found that the concordane rate of coronary heart disease was higher in MZ twin pairs (25.3%) than in DZ twins (7.4%), and the difference was statistically significant (P<0.001). The overall heritability of coronary heart disease was 19.3% (95%CI: 11.8%-26.8%). Stratified by gender, age and area, the concordane rate was still higher in MZ twin pairs than in DZ pairs. Participants who were women, aged 18-30 years or ≥60 years and lived in northern China had a higher heritability of coronary heart disease. Conclusion: The distribution of coronary heart disease in twin pairs differed in populations and areas. The prevalence of coronary heart disease was affected by genetic factors, but the effect varied with age, gender and area.

[A descriptive analysis on type 2 diabetes in twins in China]

Objective: To describe the distribution characteristics of type 2 diabetes in twins in Chinese National Twin Registry (CNTR), provide clues and evidence for revealing the influence of genetic and environmental factors for type 2 diabetes. Methods: Of all twins registered in the CNTR during 2010-2018, a total 18 855 twin pairs aged ≥30 years with complete registration information were included in the analysis. The random effect model was used to describe the population and area distribution characteristics and concordance of type 2 diabetes in twin pairs. Results: The mean age of the subjects was (42.8±10.2) years, the study subjects included 10 339 monozygotic (MZ) twin pairs and 8 516 dizygotic (DZ) twin pairs. The self-reported prevalence rate of type 2 diabetes was 2.2% in total population and there was no sighificant difference between MZ and DZ. Intra-twin pairs analysis showed that the concordance rate of type 2 diabetes was 38.2% in MZ twin pairs, and 16.0% in DZ twin pairs, the difference was statistically significant (P<0.001). The concordance rate of type 2 diabetes in MZ twin parts was higher than that in DZ twin pairs in both men and women, in different age groups and in different areas (P<0.05). Further stratified analysis showed that in northern China, only MZ twin pairs less than 60 years old were found to have a higher concordance rate of type 2 diabetes compared with DZ twin pairs (P<0.05). In southern China, the co-prevalence rate in male MZ twin pairs aged ≥60 years was still higher than that in DZ twin pairs (P<0.05). Conclusion: The twin pairs in this study had a lower self-reported prevalence of type 2 diabetes than the general population. The study results suggested that genetic factors play a role in type 2 diabetes prevalence in both men and women, in different age groups and in different areas, however, the effect might vary.

Plate-Like ZSM-5 Zeolites as Robust Catalysts for the Cracking of Hydrocarbons

Zeolites with good acid site accessibility and high diffusion rates are highly desirable catalysts, especially when dealing with bulk molecules. In this work, ZSM-5 zeolites with similar Si/Al ratios but different thicknesses along the b-axis (from ∼30 nm to ∼5 μm), namely, two plate-like ZSM-5 zeolites and two reference zeolites have been prepared and the impacts of b-axis thickness on the surface properties and catalytic cracking performances are explored. Comprehensive physiochemical studies demonstrate that reducing the b-axis thickness of the zeolite crystals endows the samples with better acid site accessibility and more external surface acid sites. Two model compounds with different molecule sizes, namely, 1,3,5-triisopropylbenzene (TIPB) and cumene, are selected to explore the catalytic cracking performances of the as-synthesized samples. The results reveal that decreasing the b-axis thickness of zeolite crystals can effectually promote the catalytic activity and stability in catalytic cracking reactions. For TIPB cracking, the greatly enhanced catalytic activity is ascribed to the enhanced acid site accessibility in plate-like ZSM-5 zeolites, and for cumene cracking, the improved catalytic stability is ascribed to the shortened diffusion length of plate-like zeolites.

Direct Propylene Epoxidation with Molecular Oxygen over Cobalt-Containing Zeolites

Direct propylene epoxidation with molecular oxygen is a dream reaction with 100% atom economy, but aerobic epoxidation is challenging because of the undesired over-oxidation and isomerization of epoxide products. Herein, we report the construction of uniform cobalt ions confined in faujasite zeolite, namely, Co@Y, which exhibits unprecedented catalytic performance in the aerobic epoxidation of propylene. Propylene conversion of 24.6% is achieved at propylene oxide selectivity of 57% at 773 K, giving a state-of-the-art propylene oxide production rate of 4.7 mmol/g_cat/h. The catalytic performance of Co@Y is very stable, and no activity loss can be observed for over 200 h. Spectroscopic analyses reveal the details of molecular oxygen activation on isolated cobalt ions, followed by interaction with propylene to produce epoxide, in which the Co²⁺-Co^δ+-Co²⁺ (2 < δ < 3) redox cycle is involved. The reaction pathway of propylene oxide and byproduct acrolein formation from propylene epoxidation is investigated by density functional theory calculations, and the unique catalytic performance of Co@Y is interpreted. This work presents an explicit example of constructing specific transition-metal ions within the zeolite matrix toward selective catalytic oxidations.

[Contrastive analysis about the postoperative clinical characteristics of elderly patients with colorectal cancer in different age groups]

Objective: To explore the postoperative clinical characteristics of elderly patients with colorectal cancer at different ages. Methods: Retrospective analysis was performed on the clinical data of 720 elderly patients with Colorectal Cancer in Beijing Hospitals from January 2012 to December 2019. There were 411 males and 309 females with a median age of 74 years. We divided the patients into young-old, old-old, oldest-old colorectal cancer patient groups and used chi-square comparative analysis of different groups of patients with clinical disease characteristics. Results: The oldest-old colorectal cancer patients tended to have normal body mass index (BMI), and the site of the disease shifted to the right. The incidence of concomitant diseases such as heart disease and hypertension increases gradually with age, and the incidence of diabetes is highest in old-old colorectal cancer patients. The proportion of open surgery was higher in the oldest-old group, but the operation time was shorter than the other two groups. In addition, the incidence of postoperative complications in elderly patients with colorectal cancer gradually increases with age, especially cardiac complications and other complications such as pneumonia, deep venous thrombosis of lower limbs, urinary retention, urinary tract infection, renal failure, cerebral hemorrhage, cerebral infarction, and so on. Conclusions: The BMI of the oldest-old patients tended to be normal, and the site of the disease shifted to the right. The incidence of heart disease, hypertension, and other concomitant diseases and postoperative complications in elderly patients with colorectal cancer gradually increase with age. Thus, the choice of treatment should be more individualized for elderly patients with colorectal cancer, and more attention should be paid to perioperative management.

Zeolite-Encaged Isolated Platinum Ions Enable Heterolytic Dihydrogen Activation and Selective Hydrogenations

Understanding the unique behaviors of atomically dispersed catalysts and the origin thereof is a challenging topic. Herein, we demonstrate a facile strategy to encapsulate Pt^δ+ species within Y zeolite and reveal the nature of selective hydrogenation over a Pt@Y model catalyst. The unique configuration of Pt@Y, namely atomically dispersed Pt^δ+ stabilized by the surrounding oxygen atoms of six-membered rings shared by sodalite cages and supercages, enables the exclusive heterolytic activation of dihydrogen over Pt^δ+···O^2- units, resembling the well-known classical Lewis pairs. The charged hydrogen species, i.e., H⁺ and H^δ-, are active reagents for selective hydrogenations, and therefore, the Pt@Y catalyst exhibits remarkable performance in the selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols and of nitroarenes to arylamines.

Privacy-Preserved EMR Information Publishing and Sharing: A Blockchain-Enabled Smart Healthcare System

Electronic Medical Records (EMR) can facilitate information publishing and sharing among doctors, hospitals, and academic researchers in a smart healthcare system. Since the personalized attributes in EMRs can be tempered by attackers or accessed by unauthorized users for malicious purposes. We construct an individual-centric privacy-preserved EMR information publishing and sharing system. First, we design an intelligent matching model using utility functions to quantitatively evaluate privacy elements and compute maximum benefits between transaction participants, i.e., EMRs publishers and EMRs requesters. After that, we classify the personalized attributes of EMRs according to healthcare applications and design a blockchain-enabled privacy-preserved framework to protect the attributes during the lifetime of data publishing and sharing. We design multiple smart contracts deployed on the blockchain framework to guarantee the identity anonymous, dynamic access control, and tracebility of transactions in a smart healthcare system. Finally, we develop a prototype system and test our approach using 100,000 EMRs. The experimental results show that the proposed privacy-preserved scheme can make stable matching and security transactions between publishers and requesters.

Stabilizing the framework of SAPO-34 zeolite toward long-term methanol-to-olefins conversion

As a commercial MTO catalyst, SAPO-34 zeolite exhibits excellent recyclability probably due to its intrinsic good hydrothermal stability. However, the structural dynamic changes of SAPO-34 catalyst induced by hydrocarbon pool (HP) species and the water formed during the MTO conversion as well as its long-term stability after continuous regenerations are rarely investigated and poorly understood. Herein, the dynamic changes of SAPO-34 framework during the MTO conversion were identified by 1D ²⁷Al, ³¹P MAS NMR, and 2D ³¹P-²⁷Al HETCOR NMR spectroscopy. The breakage of T-O-T bonds in SAPO-34 catalyst during long-term continuous regenerations in the MTO conversion could be efficiently suppressed by pre-coking. The combination of catalyst pre-coking and water co-feeding is established to be an efficient strategy to promote the catalytic efficiency and long-term stability of SAPO-34 catalysts in the commercial MTO processes, also sheds light on the development of other high stable zeolite catalyst in the commercial catalysis.

Stability of zeolite catalysts is a highly desirable property for commercial methanol to olefins conversion but extremely challenging to achieve. Here, the authors combine the catalyst pre-coking and water co-feeding to develop an efficient strategy to enhance the long-term stability of SAPO-34 catalyst.

Confinement in a Zeolite and Zeolite Catalysis

ConspectusZeolites, accompanied by their initial discovery as natural mines and the subsequent large-scale commercial production, have played indispensable roles in various fields such as petroleum refining and the chemical industry. Understanding the characteristics of zeolites, in contrast to their counterparts with similar chemical compositions and the origin thereof, is always a hot and challenging topic. Zeolites are known as intrinsic confined systems with ordered channels on the molecular scale, and structural confinement has been proposed to explain the unique chemical behaviors of zeolites. Generally, the channels of zeolites can regulate the diffusion of molecules, leading to a visible difference in molecular transportation and the ultimate shape-selective catalysis. On the other hand, the local electric field within the zeolite channels or cages can act on the guest molecules and change their energy levels. Confinement can be simply interpreted from both spatial and electronic issues; however, the nature of zeolite confinement is ambiguous and needs to be clarified.In this Account, we make a concise summary and analysis of the topics of confinement in a zeolite and zeolite catalysis from two specific views of spatial constraint and a local electric field to answer two basic questions of why zeolites and what else can we do with zeolites. First, it is shown how to construct functional sites including Brønsted acid sites, Lewis acid sites, extraframework cation sites, and entrapped metal or oxide aggregates in zeolites via confinement and how to understand the specific role of confinement in their reactivity. Second, the multiple impacts of confinement in zeolite-catalyzed reactions are discussed, which rationally lead to several unique processes, namely, Brønsted acid catalysis confined in zeolites, Lewis acid catalysis confined in zeolites, catalysis by zeolite-confined coordinatively unsaturated cation sites, and a cascade reaction within the confined space of zeolites. Overall, confinement effects do exist in zeolite systems and have already played extremely important roles in adsorption and catalysis. Although confinement might exist in many systems, the confinement by zeolites is more straightforward thanks to their well-ordered and rigid structure, deriving unique chemical behaviors within the confined space of zeolites. A zeolite is a fantastic scaffold for constructing isolated sites spatially and electrostatically confined in its matrix. Furthermore, zeolites containing well-defined transition-metal sites can be treated as inorganometallic complexes (i.e., a zeolite framework as the ligand of transition-metal ions) and can catalyze reactions resembling organometallic complexes or even metalloenzymes. The local electric field within the confined space of zeolites is strong enough to induce or assist the activation of small molecules, following the working fashion of frustrated Lewis pairs. The tactful utilization of structural confinement, both spatially and electronically, becomes the key to robust zeolites for adsorption and catalysis.

Platelike MFI Crystals with Controlled Crystal Faces Aspect Ratio

Zeolite crystals offering a short diffusion pathway through the pore network are highly desired for a number of catalytic and molecule separation applications. Herein, we develop a simple synthetic strategy toward reducing the thickness along the b-axis of MFI-type crystals, thus providing a short diffusion path along the straight channel. Our approach combines preliminary aging and a fluoride-assisted low-temperature crystallization. The synthesized MFI crystals are in the micrometer-size range along the a- and c-axis, while the thickness along the b-axis is a few tens of nanometers. The synthesis parameters controlling the formation of platelike zeolite are studied, and the factors controlling the zeolite growth are identified. The synthesis strategy works equally well with all-silica MFI (silicalite-1) and its Al- and Ga-containing derivatives. The catalytic activity of platelike ZSM-5 in the methanol-to-hydrocarbons (MTH) reaction is compared with a commercial nanosized ZSM-5 sample, as the platelike ZSM-5 exhibits a substantially extended lifetime. The synthesis of platelike MFI crystals is successfully scaled up to a kilogram scale.

Reaction kinetics and mechanism of CH4-SCR on Ru–In/H-SSZ-13

The temperature-dependent CH₄-SCR mechanism on Ru–In/H-SSZ-13 is elucidated by reaction kinetics and in situ spectroscopy analysis.

Noble Metal Particles Confined in Zeolites: Synthesis, Characterization, and Applications

Noble metal nanoparticles or subnanometric particles confined in zeolites, that is, metal@zeolite, represent an important type of functional materials with typical core-shell structure. This type of material is known for decades and recently became a research hotspot due to their emerging applications in various fields. Remarkable achievements are made dealing with the synthesis, characterization, and applications of noble metal particles confined in zeolites. Here, the most representative research progress in metal@zeolites is briefly reviewed, aiming to boost further research on this topic. For the synthesis of metal@zeolites, various strategies, such as direct synthesis from inorganic or ligand-assisted noble metal precursors, multistep postsynthesis encapsulation and ion-exchange followed by reduction, are introduced and compared. For the characterization of metal@zeolites, several most useful techniques, such as electron microscopy, X-ray based spectroscopy, infrared and fluorescence emission spectroscopy, are recommended to check the successful confinement of noble metal particles in zeolite matrix and their unique physiochemical properties. For the applications of metal@zeolites, catalysis and optics are involved with an emphasis on catalytic applications including the size-dependent catalytic properties, the sintering-resistance properties, the substrate shape-selective catalysis, and catalysis modulation by zeolite microenvironment.

[Risk factors for low anterior resection syndrome]

Objective: While low anterior resection avoided a permanent stoma, it might also cause bowel dysfunction which can significantly impact patients' quality of life. The objective of this study was to identify the incidence and risk factors for the development of bowel dysfunction following rectal surgery. Methods: Patients undergoing anterior resection for rectal neoplasm between January 2010 and December 2015 were identified from a rectal cancer database at the Department of Gastrointestinal Surgery, Beijing Hospital. All patients were asked to fill in a low anterior resection syndrome (LARS) questionnaire. Clinical factors were compared between patients with major LARS and those with minor or no LARS using conditional logistic regression. Results: There was 254 patients enrolled in the study. One hundred and eleven (44.1%) had major LARS symptoms. Neoadjuvant radiotherapy (OR=2.814, 95%CI: 1.097-5.561, P<0.001), low tumor location (OR=3.568, 95%CI: 1.159-6.546, P<0.001) and anastomotic leakage (OR=6.574, 95%CI: 1.689-15.367, P<0.001) were independent risk factors for development of major LARS symptoms. Conclusions: For patients with high risk of low anterior resection syndrome, the potential for long-term poor functional results should be discussed with patients and form a part of the decision-making in individual treatment plans. Sphincter-preserving surgery should be performed in highly selected patients to avoid major bowel dysfunction.

Murine exposure to gold nanoparticles during early pregnancy promotes abortion by inhibiting ectodermal differentiation

Background

Gold nanoparticles (AuNPs) have been widely studied for biomedical applications, although their safety and potential toxicity in pregnancy remains unknown. The aim of this study is to explore the effect of AuNPs maternal exposure at different gestational ages on fetal survival and development, as well as the potential mechanism of AuNPs affecting embryos and fetuses.

Methods

Thirty nm polyethylene glycol (PEG)-coated AuNPs (A30) were administered to pregnant mice via intravenous injection (5 μg Au/g body weight) over three days at either early or late pregnancy. Fetal abortion rate and morphological development in E16.5 were then detected in detail. The pregnant mice physiological states with A30 exposure were examined by biochemical, histological or imaging methods; and materno-fetal distribution of gold elements was assayed by electron microscopy and mass spectrometry. Murine embryonic stem cells derived embryoid-bodies or neuroectodermal cells were treated with A30 (0.0025 to 0.25 μg Au/mL) to examine A30 effects on expression levels of the germ differentiation marker genes. Tukey’s method was used for statistical analysis.

Results

Exposure to A30 during early (A30E) but not late (A30L) pregnancy caused a high abortion rate (53.5%), lower fetal survival rate and abnormal decidualization compared with non-exposed counterparts. The developmental damage caused by A30 followed an “all-or-nothing” pattern, as the non-aborted fetuses developed normally and pregnancies maintained normal endocrine values. A30 caused minor impairment of liver and kidney function of A30E but not A30L mice. TEM imaging of fetal tissue sections confirmed the transfer of A30 into fetal brain and live as aggregates. qPCR assays showed A30 suppressed the expression of ectodermal, but not mesodermal and endodermal differentiation markers.

Conclusions

These results illustrate that maternal A30 exposure in early pregnant results in A30 transfer into embryonic tissues, inhibiting ectodermal differentiation of embryonic stem cells, leading to abnormal embryonic development and abortion. While exposure to A30 during late pregnancy had little or no impact on dams and fetuses. These findings suggest the safety of biomedical applications employing AuNPs during pregnancy is strongly influenced by fetal maturity and gestational age at exposure and provide the clues for AuNPs safe application period in pregnancy.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0061-2) contains supplementary material, which is available to authorized users.

[Analysis of chromosome in 1 324 patients with oligozoospermia or azoosperm]

OBJECTIVE

To explore the incidience of chromosome abnormality of the patients with oligozoospermia or azoospermia and male infertility, to discuss the relationship between the quantitative and structural abnormality of chromosome and to lay the foundation for the clinical diagnosis and consultation.

METHODS

A retrospective analysis was conducted from January 1, 2015 to May 1, 2016, in the Center for Reproduction Medicine, the Second Hospital of Jilin University, with male reproductive abnormalities history excluded. In the study, 1 324 cases were included with 448 cases of azoospermia and 876 cases of oligozoospermia. All the patients through ultrasound examination, color Doppler ultrasonography, the seminal plasma Zn determination, their hormone level determination, chromosome karyotype (the perinatal blood samples were obtained from the 1 324 patients with oligozoospermia or azoospermia for lymphocyte culture, then chromosomal specimens were prepared, G-banding analyses combined with clinical data were used to statistically analyze the incidence of chromosomal abnormality), Y chromosome azoospermia factor [PCR technique was used to detect SY157 locus, SY254 locus, and SY255 locus in male Y chromosome azoospermia factor (AZF) gene of the patients with oligozoospermia or azoospermia]. The relationship between chromosome abnormalities and oligozoospermia or azoospermia were analyzed.

RESULTS

Among the 876 cases of oligospermia patients, 78 cases were chromosome number abnormality and chromosomal structural abnormality, the abnormal number of sex chromosomes in 22 cases, and sex chromosomes and chromosome structural abnormalities in 56 cases; in the 448 cases of azoospermia patients, 91 cases were chromosomal structural abnormality and chromosome number abnormality, of them, 78 cases were of abnormal number of sex chromosomes, and 13 cases were of abnormal structure. In addition, 137 cases were of chromosome polymorphism in all the 1 324 patients, The incidence of Y chromosome abnormality in azoospermatism was higher than that of the 43 patients with Y chromosome AZF microdeletion. In addition, the asthenospermia and recurrent spontaneous abortion were closely related to Y chromosome abnormality and the chromosome translocations and inversions.

CONCLUSION

Oligozoospermia and azoospermia patients with abnormal chromosome karyotype have high incidence rate, and chromosome karyotype analyses were carried out on it, which is conducive to clinical diagnosis for the patients with abnormal chromosome karyotype. There is a close relationship between male infertility and abnormal karyotype. It is conducive to clinical diagnosis for the patients with infertility through chromosome karyotye analysis, which also provides evidence for genetic counseling.

[A complex chromosome translocation with male infertility of karyotype analysis and literature review]

One case of family chromosomal karyotype with complex chromosomal translocation and male infertility was reported. This case is a male, 30 years old, Han nationality, who did not receive contraception for 3 years after marriage. The phenotype and intelligence of the patients were normal, and there were no abnormalities in the external genitalia. No abnormalities were found in the prostate and spermatic vein. There was no history of parotitis or testicular trauma, no history of smoking, drinking history, denial of harmful substances and history of radioactive contact. There were no similar patients in the family, and the secondary sex was normal. The routine semen examination suggested that the active sperm was seldom seen. There were no obvious abnormalities in the serum endocrine examination of the patient. Cytogenetic examination: the patient's karyotype 46XY, t (10; 18; 21) (q22; p11.2; q11.2). There was no deletion in locus sY84, sY86, sY127, sY134, sY143, sY254 and sY255. His wife's examination showed no obvious abnormality, and her karyotype was normal. The parents of the patients were not close relatives. Their father's chromosome karyotype analysis was 46, XY, and Y chromosome microdeletion was normal. The chromosome karyotype of the parent was 46XX, t (10; 18; 21), and the parents of the patient also had a daughter, whose phenotype and intellectual development were normal, chromosome karyotype 46XX, t (10; 18; 21). In this case, the patient's balance translocation should be inherited by the mother. Because of the normal phenotype of the patient, there was no loss of genetic material, but the abnormal chromosomes might be passed to the offspring, and the proportion of the unbalanced gametes was very high. Through systematic review and review of the cases, it was concluded that the balanced translocation carriers only changed the relative position of the translocation segments on the chromosomes, retained the total number of the original genes, only changed the relative position of the genes on the chromosomes, and had no serious effect on the role of the gene and the development of the individual. The phenotype was normal. The patients were given symptomatic treatment to improve semen quality. It is recommended that pre-implantation genetic screening/diagnosis(PGS/PGD) be performed if necessary. It is to guide married men and women to choose the appropriate childbearing age, avoid unhealthy environmental contacts, and strengthen genetic screening before and after pregnancy, so as to achieve the goal of eugenics.

Construction of Bifunctional Co/H-ZSM-5 Catalysts for the Hydrodeoxygenation of Stearic Acid to Diesel-Range Alkanes

Bifunctional Co/H-ZSM-5 zeolites were prepared by a surface organometallic chemistry grafting route, namely, by the stoichiometric reaction between cobaltocene and the Brønsted acid sites in zeolites. The catalyst was applied to a model reaction of the catalytic hydrodeoxygenation of stearic acid (SA). The cobalt species existed in the form of isolated Co²⁺ ions at the exchange positions after grafting, transformed to CoO species on the surface of the zeolite, stabilized inside the zeolite channels upon calcination in air, and finally reduced by hydrogen to homogeneous clusters of metallic cobalt species approximately 1.5 nm in size. During this process, the Brønsted acid sites of the H-ZSM-5 zeolites were preserved with a slightly reduced acid strength. The as-prepared bifunctional catalyst exhibited an approximately 16 times higher activity for the hydrodeoxygenation of SA (2.11 g_SA  g_cat^-1  h^-1 ) than the reference catalyst (0.13 g_SA  g_cat^-1  h^-1 ) prepared by solid-state ion exchange and a high C₁₈ /C₁₇ ratio of approximately 24. The remarkable hydrodeoxygenation performance of the bifunctional Co/H-ZSM-5 was owed to the effective synergy between the uniformed metallic cobalt clusters and the Brønsted acid sites in H-ZSM-5. The simplified reaction network and kinetics of the SA hydrodeoxygenation catalyzed by the as-prepared bifunctional Co/H-ZSM-5 zeolites were also investigated.

Oxidative dehydrogenation of propane over Pt–Sn/Si-beta catalysts: key role of Pt–Sn interaction

Bimetallic Pt–Sn catalysts supported on dealuminated Si-beta zeolite were prepared via wet impregnation and the nanoscale close contact between Pt and Sn species in Pt–Sn/Si-beta was confirmed by electron microscopy analyses.

One-pot construction of Fe/ZSM-5 zeolites for the selective catalytic reduction of nitrogen oxides by ammonia

A simple one-step hydrothermal approach is developed to construct Fe/ZSM-5 zeolites for the selective catalytic reduction of nitrogen oxides by ammonia.

Fabrication of WO2.72/RGO nano-composites for enhanced photocatalysis

WO_2.72/RGO nano-composites exhibit remarkable photocatalytic activity in both oxygen evolution from water splitting and selective oxidation of benzyl alcohol due to the synergetic effects between WO_2.72 and RGO.

A simple synthesis of Ga2O3 and GaN nanocrystals

A simple top-down strategy to α-Ga₂O₃ and GaN nanocrystals is developed and the morphology-dependent optical properties of α-Ga₂O₃ crystals are established.