Advancing single-cell RNA-seq data analysis through the fusion of multi-layer perceptron and graph neural network.

The advancement of single-cell sequencing technology has smoothed the ability to do biological studies at the cellular level. Nevertheless, single-cell RNA sequencing (scRNA-seq) data presents several obstacles due to the considerable heterogeneity, sparsity and complexity. Although many machine-learning models have been devised to tackle these difficulties, there is still a need to enhance their efficiency and accuracy. Current deep learning methods often fail to fully exploit the intrinsic interconnections within cells, resulting in unsatisfactory results. Given these obstacles, we propose a unique approach for analyzing scRNA-seq data called scMPN. This methodology integrates multi-layer perceptron and graph neural network, including attention network, to execute gene imputation and cell clustering tasks. In order to evaluate the gene imputation performance of scMPN, several metrics like cosine similarity, median L1 distance and root mean square error are used. These metrics are utilized to compare the efficacy of scMPN with other existing approaches. This research utilizes criteria such as adjusted mutual information, normalized mutual information and integrity score to assess the efficacy of cell clustering across different approaches. The superiority of scMPN over current single-cell data processing techniques in cell clustering and gene imputation investigations is shown by the experimental findings obtained from four datasets with gold-standard cell labels. This observation demonstrates the efficacy of our suggested methodology in using deep learning methodologies to enhance the interpretation of scRNA-seq data.

Amorphization Activated Multimetallic Pd Alloys for Boosting Oxygen Reduction Catalysis.

Amorphous nanomaterials have drawn extensive attention owing to their unique features, while amorphization on noble metal nanomaterials still remains formidably challenging. Herein, we demonstrate a universal strategy to synthesize amorphous Pd-based nanomaterials from unary to quinary metals through the introduction of phosphorus (P). The amorphous Pd-based nanoparticles (NPs) exhibit generally promoted oxygen reduction reaction (ORR) activity and durability compared with their crystalline counterparts. Significantly, the quinary P-PdCuNiInSn NPs, benefiting from the amorphous structure and multimetallic component effect, exhibit mass activities as high as 1.04 A mgPd-1 and negligible activity decays of 1.8% among the stability tests, which are much better than values for original Pd NPs (0.134 A mgPd-1 and 28.4%). Experimental and theoretical analyses collectively reveal that the synergy of P-induced amorphization and the expansion of metallic components can considerably lower the free energy changes in the rate-determined step, thereby explaining the positive correlation with the catalytic activity.

Alleviating OH Blockage on the Catalyst Surface by the Puncture Effect of Single-Atom Sites to Boost Alkaline Water Electrolysis.

Nonprecious transition metal catalysts have emerged as the preferred choice for industrial alkaline water electrolysis due to their cost-effectiveness. However, their overstrong binding energy to adsorbed OH often results in the blockage of active sites, particularly in the cathodic hydrogen evolution reaction. Herein, we found that single-atom sites exhibit a puncture effect to effectively alleviate OH blockades, thereby significantly enhancing the alkaline hydrogen evolution reaction (HER) performance. Typically, after anchoring single Ru atoms onto tungsten carbides, the overpotential at 10 mA·cm-2 is reduced by more than 130 mV (159 vs 21 mV). Also, the mass activity is increased 16-fold over commercial Pt/C (MA100 = 17.3 A·mgRu-1 vs 1.1 A·mgPt-1, Pt/C). More importantly, such electrocatalyst-based alkaline anion-exchange membrane water electrolyzers can exhibit an ultralow potential (1.79 Vcell) and high stability at an industrial current density of 1.0 A·cm-2. Density functional theory (DFT) calculations reveal that the isolated Ru sites could weaken the surrounding local OH binding energy, thus puncturing OH blockage and constructing bifunctional interfaces between Ru atoms and the support to accelerate water dissociation. Our findings exhibit generality to other transition metal catalysts (such as Mo) and contribute to the advancement of industrial-scale alkaline water electrolysis.

Newly graphene/polypyrrole (rGO/PPy) modified carbon felt as bio-cathode in bio-electrochemical systems (BESs) achieving complete denitrification.

Nitrate reduction in bio-electrochemical systems (BESs) has attracted wide attention due to its low sludge yields and cost-efficiency advantages. However, the high resistance of traditional electrodes is considered to limit the denitrification performance of BESs. Herein, a new graphene/polypyrrole (rGO/PPy) modified electrode is fabricated via one-step electrodeposition and used as cathode in BES for improving nitrate removal from wastewater. The formation and morphological results support the successful formation of rGO/PPy nanohybrids and confirm the part covalent bonding of Py into GO honeycomb lattices to form a three-dimensional cross-linked spatial structure. The electrochemical tests indicate that the rGO/PPy electrode outperforms the unmodified electrode due to the 3.9-fold increase in electrochemical active surface area and 6.9-fold decrease in the charge transfer resistance (Rct). Batch denitrification activity tests demonstrate that the BES equipped with modified rGO/PPy biocathode could not only achieve the full denitrification efficiency of 100% with energy recovery (15.9 × 10-2 ± 0.14 A/m2), but also favor microbial attach and growth with improved biocompatible surface. This work provides a feasible electrochemical route to fabricate and design a high-performance bioelectrode to enhance denitrification in BESs.

Intrinsic Activity Identification of Noble Metal Single-Sites for Electrocatalytic Chlorine Evolution.

Single-atom catalysts with maximal atom-utilization have emerged as promising alternatives for chlorine evolution reaction (CER) toward valuable Cl2 production. However, understanding their intrinsic CER activity has so far been plagued due to the lack of well-defined atomic structure controlling. Herein, we prepare and identify a series of atomically dispersed noble metals (e.g., Pt, Ir, Ru) in nitrogen-doped nanocarbons (M1-N-C) with an identical M-N4 moiety, which allows objective activity evaluation. Electrochemical experiments, operando Raman spectroscopy, and quasi-in situ electron paramagnetic resonance spectroscopy analyses collectively reveal that all the three M1-N-C proceed the CER via a direct Cl-mediated Vomer-Heyrovský mechanism with reactivity following the trend of Pt1-N-C>Ir1-N-C>Ru1-N-C. Density functional theory (DFT) calculations reveal that this activity trend is governed by the binding strength of Cl*-Cl intermediate (ΔGCl*-Cl) on M-N4 sites (Pt

Tandem Electro-Thermo-Catalysis for the Oxidative Aminocarbonylation of Arylboronic Acids to Amides from CO2 and Water.

Direct CO2 electroreduction to valuable chemicals is critical for carbon neutrality, while its main products are limited to simple C1 /C2 compounds, and traditionally, the anodic O2 byproduct is not utilized. We herein report a tandem electrothermo-catalytic system that fully utilizes both cathodic (i.e., CO) and anodic (i.e., O2 ) products during overall CO2 electrolysis to produce valuable organic amides from arylboronic acids and amines in a separate chemical reactor, following the Pd(II)-catalyzed oxidative aminocarbonylation mechanism. Hexamethylenetetramine (HMT)-incorporated silver and nickel hydroxide carbonate electrocatalysts were prepared for efficient coproduction of CO and O2 with Faradaic efficiencies of 99.3 % and 100 %, respectively. Systematic experiments, operando attenuated total reflection surface-enhanced Fourier transform infrared spectroscopy characterizations and theoretical studies reveal that HMT promotes *CO2 hydrogenation/*CO desorption for accelerated CO2 -to-CO conversion, and O2 inhibits reductive deactivation of the Pd(II) catalyst for enhanced oxidative aminocarbonylation, collectively leading to efficient synthesis of 10 organic amides with high yields of above 81 %. This work demonstrates the effectiveness of a tandem electrothermo-catalytic strategy for economically attractive CO2 conversion and amide synthesis, representing a new avenue to explore the full potential of CO2 utilization.

Electrochemical ammonia synthesis under ambient conditions using TM-embedded porphine-fused sheets as single-atom catalysts.

In this research, we systematically investigated the reaction mechanism and electrocatalytic properties of transition metal anchored two-dimensional (2D) porphine-fused sheets (TM-Por) as novel single-atom catalysts (SACs) for the electrochemical nitrogen reduction reaction (eNRR) under ambient conditions. Using high-throughput screening and first-principles calculations based on the density functional theory (DFT) method, three eNRR catalyst candidates, i.e. Mo-Por, Tc-Por, and Nb-Por, were screened out, with the eNRR onset potentials on them being -0.36, -0.53, and -0.74 V, respectively. Furthermore, these catalyst candidates all have good stability and selectivity. Analyzing the band structures found that these catalyst candidates all are metallic, which is needed for good electrocatalysts. Ab initio molecular dynamics (AIMD) simulations show that these catalyst candidates have good stability at 500 K. It is hoped that our work will open up new possibilities for the experimental synthesis of electrochemical ammonia catalysts.

Fabrication of modified electrode by reduced graphene oxide (rGO) and polyaniline (PANI) for enhancing azo dye decolorization in bio-electrochemical systems (BESs).

Bio-electrochemical systems (BESs) have attracted wide attention in the field of wastewater treatment owing to their fast electron transfer rate and high performance. Unfortunately, the low electro-chemical activity of carbonaceous materials commonly used in BESs remains a bottleneck for their practical applications. Especially, for refractory pollutants remediation, the efficiency is largely limited by the cathode property in term of (bio)-electrochemical reduction of highly oxidized functional groups. Herein, a reduced graphene oxide (rGO) and polyaniline (PANI) modified electrode was fabricated via two-step electro-deposition using carbon brush as raw material. Benefiting from the modified graphene sheets and PANI nanoparticles, the rGO/PANI electrode shows highly conductive network with the electro-active surface area increased by 12 times (0.013 mF cm-2) and the charge transfer resistance decreased by 92% (0.23Ω) comparing with the unmodified one. Most importantly, the rGO/PANI electrode used as abiotic cathode achieves highly efficient azo dye removal from wastewater. The highest decolorization efficiency reaches 96 ± 0.03% within 24 h and the maximum decolorization rate is as high as 20.9 ± 1.45 g h-1·m-3. The features of improved electro-chemical activity and enhanced pollutant removal efficiency provide a new insight toward development of high performance BESs via electrode modification for practical application.

[Clinical Outcome and Risk Factors of Treatment Failure of Peritoneal Dialysis Associated Peritonitis Caused by Klebsiella Pneumoniae:A Multicenter Study].

Objective To investigate the treatment outcomes,prognosis,and risk factors of treatment failure of peritoneal dialysis associated peritonitis (PDAP) caused by Klebsiella pneumoniae,and thus provide clinical evidence for the prevention and treatment of this disease. Methods The clinical data of PDAP patients at four peritoneal dialysis centers from January 1,2014 to December 31,2019 were collected retrospectively.The treatment outcomes and prognosis were compared between the patients with PDAP caused by Klebsiella.pneumoniae and that caused by Escherichia coli.Kaplan-Meier method was employed to establish the survival curve of technical failure,and multivariate Logistic regression to analyze the risk factors of the treatment failure of PADP caused by Klebsiella pneumoniae. Results In the 4 peritoneal dialysis centers,1034 cases of PDAP occurred in 586 patients from 2014 to 2019,including 21 cases caused by Klebsiella pneumoniae and 98 cases caused by Escherichia coli.The incidence of Klebsiella pneumoniae caused PDAP was 0.0048 times per patient per year on average,ranging from 0.0024 to 0.0124 times per patient per year during 2014-2019.According to the Kaplan-Meier survival curve,the technical failure rate of Klebsiella pneumoniae caused PDAP was higher than that of Escherichia coli caused PDAP (P=0.022).The multivariate Logistic regression model showed that long-term dialysis was an independent risk factor for the treatment failure of Klebsiella pneumoniae caused PDAP (OR=1.082,95%CI=1.011-1.158,P=0.023).Klebsiella pneumoniae was highly sensitive to amikacin,meropenem,imipenem,piperacillin,and cefotetan,and it was highly resistant to ampicillin (81.82%),cefazolin (53.33%),tetracycline (50.00%),cefotaxime (43.75%),and chloramphenicol (42.86%). Conclusion The PDAP caused by Klebsiella pneumoniae had worse prognosis than that caused by Escherichia coli,and long-term dialysis was an independent risk factor for the treatment failure of Klebsiella pneumoniae caused PDAP.

Endoscopic thyroidectomy via the combined trans-oral and chest approach for cT1-2N1bM0 papillary thyroid carcinoma.

BACKGROUND: Recent years there have been witnessed considerable advances in endoscopic selective lateral neck dissection (LND). However, dissection of lymph nodes at level IV and level VI via the chest approach is inherently challenging. In this study, we used combined trans-oral and chest approach for endoscopic thyroidectomy in patients with cT1-2N1bM0 papillary thyroid carcinoma (PTC). METHODS: Clinical characteristics and surgical outcomes of ten patients with cT1-2N1bM0 PTC who underwent endoscopic thyroidectomy via combination of trans-oral and chest approach between September 2020 and September 2021 were retrospectively reviewed. RESULTS: All 10 patients successfully underwent total thyroidectomy and selective LND via chest approach, while central neck dissection (CND) and supplementary dissection of lymph nodes at level IV were performed via the trans-oral approach. The mean number of positive/retrieved level II, III-IV, and VI lymph nodes were 0.6 ± 1.0/9.8 ± 5.0, 4.6 ± 2.8/23.1 ± 4.7, and 4.9 ± 3.4/10.3 ± 4.6, respectively. Four patients developed transient hypoparathyroidism which spontaneously resolved within 1 month. Five patients developed numbness of lateral neck and ear and one patient experienced limb lift restriction. No other complications or tumor recurrence occurred during follow-up. CONCLUSION: It is feasible to perform total thyroidectomy, CND, and selective LND via combined trans-oral and chest approach, and satisfactory short-term outcomes were observed in this cohort. This approach may offer one more option for cT1-2N1bM0 PTC patients, especially those in whom metastatic lymph nodes at level IV or level VI are detected by preoperative examination.

Genetic analysis of developmental and epileptic encephalopathy caused by novel biallelic SZT2 gene mutations in three Chinese Han infants: a case series and literature review.

BACKGROUND: Developmental and epileptic encephalopathy (DEE) exhibits phenotypic and genetic heterogeneity. Biallelic variants of the SZT2 gene can lead to DEE18, of which few cases have been reported. This study aimed to analyze the potential pathogenic factors in three cases of DEE18. METHODS: Trio-whole exome sequencing and crystal structure simulation analysis were performed, along with a literature review of DEE18 cases. RESULTS: All three patients had compound heterozygous variants in the SZT2 gene (patient 1, c.2887A > G/c.7970G > A; patient 2, c.3508A > G/c.7936C > T; and patient 3, c.2489G > T/c.8640_8641insC). The variants were predicted to have structural effects on the protein. Particularly, c.3508A > G/p.Ser1170Gly may lead to impaired binding of SZT2 to GATOR1, potentially resulting in the overactivation of the mTORC1 signaling pathway, causing seizures. Through the literature review, we observed that 27 patients with DEE had different degrees of intellectual and developmental disorders (DDs), and the variants leading to protein truncation cause severe DD and refractory epilepsy. Therefore, the phenotypic severity of patients may be related to the residual activity of variant SZT2 protein. CONCLUSION: We provide recently developed knowledge on the DEE18 genotype-phenotype spectrum and suggest that gene detection is of great value for the accurate diagnosis of patients with early-onset epilepsy. Further research is required for the development of individualized interventions for patients with DEE.

Safety and feasibility of the transoral endoscopic thyroidectomy vestibular approach with neuroprotection techniques for papillary thyroid carcinoma.

BACKGROUND: This study aimed to evaluate the feasibility and safety of the trans-oral endoscopic thyroidectomy vestibular approach (TOETVA) with neuroprotection techniques for the surgical management of papillary thyroid carcinoma (PTC). METHODS: Patients with PTC who underwent TOETVA between December 2016 and July 2020 were included in this study, and their relevant clinical characteristics, operational details, and surgical outcomes were reviewed and extracted from their medical records for further analysis. RESULTS: A total of 75 patients successfully underwent TOETVA with zero conversions. Unilateral lobectomy with isthmectomy and total thyroidectomy were completed for 58 and 17 patients, respectively, all using our unique neuroprotective procedure and ipsilateral central neck dissection (CND). The mean number of retrieved lymph nodes versus positive lymph nodes was 6.8 ± 3.7 vs. 1.5 ± 2.3. Postoperative complications included three cases of transient superior laryngeal nerve (SLN) palsy (4.0%), five cases of transient recurrent laryngeal nerve (RLN) palsy (6.7%), 14 cases of transient hypoparathyroidism (18.7%), two cases of numb chin (2.7%) and two cases of flap perforation (2.7%). The follow-up period for patients with PTC lasted for 15.6 ± 10.9 months, during which no other complications or tumor recurrence were observed. CONCLUSION: TOETVA can be safely performed for patients with PTC with satisfactory results during the short-term follow-up period. Our neuroprotection techniques can be integrated into TOETVA, which is worth recommending for PTC patients who desire better cosmetic surgical outcomes.

[Clinical Characteristics and Treatment Outcome of Pseudomonas Peritoneal Dialysis-associated Peritonitis].

Objective To explore the clinical characteristics and treatment of Pseudomonas peritoneal dialysis-associated peritonitis(PsP). Methods The data of patients receiving peritoneal dialysis in four tertiary hospitals in Jilin province from 2015 to 2019 were retrospectively analyzed.According to the etiological classification,the patients with peritoneal dialysis-associated peritonitis(PDAP)were classified into PsP group and non-PsP group.The incidence of PsP was calculated,and the clinical characteristics and treatment outcomes of the two groups were compared.Kaplan-Meier method was used to draw the survival curve,and Cox regression was performed to analyze the risk factors affecting the technical failure of PsP.The treatment options of Pseudomonas aeruginosa-caused PDAP and the drug sensitivity of PsP were summarized. Results A total of 1530 peritoneal dialysis patients with complete data were included in this study,among which 439 patients had 664 times of PDAP.The incidence of PsP was 0.007 episodes/patient-year.PsP group had higher proportion of refractory peritonitis(41.38% vs.19.69%,P=0.005),lower cure rate(55.17% vs.80.79%, P=0.001),and higher extubation rate(24.14% vs.7.09%,P=0.003)than non-PsP group.The technical survival rate of PsP group was lower than that of non-PsP group(P<0.001).Multivariate Cox regression analysis showed that Pseudomonas aeruginosa was an independent risk factor for technical failure in patients with PsP(HR=9.020,95%CI=1.141-71.279,P=0.037).Pseudomonas was highly sensitive to amikacin,meropenem,and piperacillin-tazobactam while highly resistant to compound sulfamethoxazole,cefazolin,and ampicillin. Conclusion The treatment outcome of PsP is worse than that of non-PsP,and Pseudomonas aeruginosa is an independent risk factor for technical failure of PsP.

Tailoring Unsymmetrical-Coordinated Atomic Site in Oxide-Supported Pt Catalysts for Enhanced Surface Activity and Stability.

The catalytic properties of supported metal heterostructures critically depend on the design of metal sites. Although it is well-known that the supports can influence the catalytic activities of metals, precisely regulating the metal-support interactions to achieve highly active and durable catalysts still remain challenging. Here, the authors develop a support effect in the oxide-supported metal monomers (involving Pt, Cu, and Ni) catalysts by means of engineering nitrogen-assisted nanopocket sites. It is found that the nitrogen-permeating process can induce the reconstitution of vacancy interface, resulting in an unsymmetrical atomic arrangement around the vacancy center. The resultant vacancy framework is more beneficial to stabilize Pt monomers and prevent diffusion, which can be further verified by the density functional theory calculations. The final Pt-N/SnO2 catalysts exhibit superior activity and stability for HCHO response (26.5 to 15 ppm). This higher activity allows the reaction to proceed at a lower operating temperature (100 °C). Incorporated with wireless intelligent-sensing system, the Pt-N/SnO2 catalysts can further achieve continuous monitoring of HCHO levels and cloud-based terminal data storage.

Properties and Detailed Adsorption of CO2 by M2(dobpdc) with N,N-Dimethylethylenediamine Functionalization.

We have systematically investigated the CO2 adsorption performance and microscopic mechanism of N,N-dimethylethylenediamine (mm-2) appended M2(dobpdc) (dobpdc4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate; M = Mg, Sc-Zn) with density functional theory. These calculations show that the mm-2 has strong interactions with the open metal site of these structures via the first amine, and the mm-2 binding energies are generally between 123 and 172 kJ/mol. After the CO2 is attached, the ammonium carbamate molecule is created by insertion. The CO2 adsorption energies (31-81 kJ/mol) depend on the metal used (Mg; Sc-Zn). The microscopic mechanism of the CO2 adsorption process is presented at the atomic level, and the detailed potential energy surface and reaction path information are provided. The CO2 molecule and mm-2 grafted M2(dobpdc) are firstly combined via physical interactions, and then, the complex is converted into an N-coordinated zwitterion intermediate over a large energy barrier (1.02-1.51 eV). Finally, the structure is rearranged into a stable ammonium carbamate configuration through a small energy barrier (0.05-0.25 eV). We hope that this research will contribute to the understanding and production of real-world carbon capture materials.

Compressive Strain Modulation of Single Iron Sites on Helical Carbon Support Boosts Electrocatalytic Oxygen Reduction.

Designing and modulating the local structure of metal sites is the key to gain the unique selectivity and high activity of single metal site catalysts. Herein, we report strain engineering of curved single atomic iron-nitrogen sites to boost electrocatalytic activity. First, a helical carbon structure with abundant high-curvature surface is realized by carbonization of helical polypyrrole that is templated from self-assembled chiral surfactants. The high-curvature surface introduces compressive strain on the supported Fe-N4 sites. Consequently, the curved Fe-N4 sites with 1.5 % compressed Fe-N bonds exhibit downshifted d-band center than the planar sites. Such a change can weaken the bonding strength between the oxygenated intermediates and metal sites, resulting a much smaller energy barrier for oxygen reduction. Catalytic tests further demonstrate that a kinetic current density of 7.922 mA cm-2 at 0.9 V vs. RHE is obtained in alkaline media for curved Fe-N4 sites, which is 31 times higher than that for planar ones. Our findings shed light on modulating the local three-dimensional structure of single metal sites and boosting the catalytic activity via strain engineering.

Formation Mechanism of Ammonium Carbamate for CO2 Uptake in N,N'-Dimethylethylenediamine Grafted M2(dobpdc).

The adsorption properties and formation mechanism of ammonium carbamate for CO2 capture in N,N'-dimethylethylenediamine (mmen) grafted M2(dobpdc) (dobpdc4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate; M = Mg, Sc-Zn, except Ni) have been studied via density functional theory (DFT) calculations. We see that the mmen molecule is joined to the metal site via a M-N bond and has hydrogen bonding with neighboring mmen molecules. The binding energies of mmen range from 135.4 to 184.0 kJ/mol. CO2 is captured via insertion into the M-N bond of mmen-M2(dobpdc), forming ammonium carbamate. The CO2 binding energies (35.2 to 92.2 kJ/mol) vary with different metal centers. Furthermore, the Bader charge analysis shows that the CO2 molecules acquire 0.42 to 0.47 |e|. This charge is mainly contributed by the mmen, and a small additional amount is from the metal atom bonded with the CO2. The preferred reaction pathway is a two-step reaction. In the first step, the hydrogen bonded complex B changes into an N-coordinated intermediate D with high barriers (0.69 to 1.58 eV). The next step involves the translation and rotation of the chain in the intermediate D, resulting in the formation of the final O-coordinated product I with barriers of 0.22 to 0.61 eV. The higher barriers of CO2 reaction with mmen-M2(dobpdc) relative to attack the primary amine might be due to the larger steric hindrance of mmen. We hope this work will contribute to an improved understanding and development of future amine-grafted materials for efficient CO2 capture.

Elucidation of the Underlying Mechanism of CO2 Capture by Ethylenediamine-Functionalized M2(dobpdc) (M = Mg, Sc-Zn).

We, for the first time, systematically investigated the crystal structures, adsorption properties, and microscopic mechanism of CO2 capture with ethylenediamine (en)-appended isostructural M2(dobpdc) materials (M = Mg, Sc-Zn), using spin polarized density functional theory (DFT) calculations. The binding energies of en range from 142 to 210 kJ/mol. The weakest binding materials are en-Cr2(dobpdc) and en-Cu2(dobpdc). Two typical models, the pair model and the chain model, have been considered for CO2 adsorption. Generally, the chain model is more stable than the pair model. The CO2 adsorption energies of the chain model are in the range of 30-96 kJ/mol, with a strong metal dependence. Among these, the en-Sc2(dobpdc) and en-Cu2(dobpdc) have the highest and lowest CO2 adsorption energies, respectively. Moreover, the dynamic progress of CO2 adsorption has been unveiled via exploration of the full reaction pathway, including transition states and intermediates. First, the CO2 molecule interacts with en-MOFs to form a physisorbed complex with a shallow potential well. This is followed by overcoming a relatively large energy barrier to form a chemisorbed complex. Finally, ammonium carbamate is formed along the one-dimensional channels within the pore with a small energy barrier for configuration transformation. These results agree well with the experimental observations. Understanding the detailed microscopic mechanism of CO2 capture is quite crucial for improving our fundamental knowledge base and potential future applications. This work will improve our understanding of CO2 adsorption with amine functionalized MOFs. We expect our results to stimulate future experimental and theoretical research and advance the development of this field.

Disclosing the microscopic mechanism and adsorption properties of CO2 capture in N-isopropylethylenediamine appended M2(dobpdc) series.

The detailed picture of the microscopic mechanism for CO2 capture in N-isopropylethylenediamine (i-2) functionalized M2(dobpdc) (dobpdc4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate; M = Mg, Sc-Zn) has been determined for the first time via systematic computations with van der Waals (vdW) corrected density functional theory (DFT) methods. The results show that acting as a Lewis base, the i-2 molecule can strongly interact with the acidic open metal sites of M2(dobpdc) via its primary amine with binding energies of 132 to 178 kJ mol-1 for different metals. After exposure to gaseous CO2, CO2 is captured by inserting into the metal-N bond. The corresponding CO2 binding energies (43-69 kJ mol-1) vary depending on the metal centers. i-2-Sc2(dobpdc) and i-2-Mg2(dobpdc) with high CO2 binding energies have promising potential for CO2 capture. Moreover, the results demonstrate that the CO2 capture process involves two steps, consisting of simultaneous nucleophilic attack of the CO2 onto the metal-bound N atom with proton transfer. This results in the formation of a zwitterion intermediate (step1), and then rearrangement of the zwitterion intermediate into the final product ammonium carbamate (step2). The first step with relatively high barriers (0.99-1.49 eV) is rate-determining. The second step with low barriers (less than 0.50 eV) can easily occur and will promote the reaction. This work uncovers the complicated microscopic mechanism of CO2 capture with i-2 functionalized MOFs at the molecular level. This study provides fundamental understanding of the adsorption process and insights into the design and synthesis of highly efficient CO2 capture materials.

[A Case of Congenital Nephrotic Syndrome of the Finnish Type].

A 5 +-day-old male patient was hospitalized due to a significant increase of urine protein for 5 + d. A 36 +4 weeks preterm male infant was found with III° polluted amniotic fluid and excessive placenta, presented with proteinuria, hypoproteinemia, and progressive edema after birth. Two heterozygous mutations of NPHS1 gene, c.3325C>T (p.Arg1109*) and c.2479C>T (p.Arg827*), were found through the whole exon gene detection. The latter has not been reported domestically and the diagnosis of congenitalnephrotic syndrome of the Finnish type (CNF) is definite. The report of c.2479C>T mutation gene will expand the mutation spectrum of CNF gene data in China. Early genetic testing is recommended for cryptogenic congenital nephrotic syndrome (CNS) and early genetic diagnosis of CNF is important for prognostic evaluation, genetic counseling and clinical management.