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1.
Dev Cell ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38636517

RESUMO

During enteric nervous system (ENS) development, pioneering wavefront enteric neural crest cells (ENCCs) initiate gut colonization. However, the molecular mechanisms guiding their specification and niche interaction are not fully understood. We used single-cell RNA sequencing and spatial transcriptomics to map the spatiotemporal dynamics and molecular landscape of wavefront ENCCs in mouse embryos. Our analysis shows a progressive decline in wavefront ENCC potency during migration and identifies transcription factors governing their specification and differentiation. We further delineate key signaling pathways (ephrin-Eph, Wnt-Frizzled, and Sema3a-Nrp1) utilized by wavefront ENCCs to interact with their surrounding cells. Disruptions in these pathways are observed in human Hirschsprung's disease gut tissue, linking them to ENS malformations. Additionally, we observed region-specific and cell-type-specific transcriptional changes in surrounding gut tissues upon wavefront ENCC arrival, suggesting their role in shaping the gut microenvironment. This work offers a roadmap of ENS development, with implications for understanding ENS disorders.

2.
J Pediatr Surg ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38508971

RESUMO

OBJECTIVE AND DESIGN: Hirschsprung disease-associated enterocolitis (HAEC) is a common life-threatening complication of Hirschsprung disease (HSCR). We aimed to investigate the effectiveness, long-term safety and the underlying mechanisms of Mesenchymal stem cells (MSCs) based therapy for HAEC. MATERIAL OR SUBJECTS: Specimens from HSCR and HAEC patients were used to assess the inflammatory condition. Ednrb knock-out mice was used as HAEC model. MSCs was intraperitoneally transplanted into HAEC mice. The therapy effects, long-term outcome, safety and toxicity and the mechanism of MSCs on the treatment of HAEC were explored in vivo and in vitro. RESULTS: Intestinal M1 macrophages infiltration and severe inflammation condition were observed in HAEC. After the injection of MSCs, HAEC mice showed significant amelioration of the inflammatory injury and inhibition of M1 macrophages infiltration. The expression levels of pro-inflammatory cytokines (TNF-α and IFN-γ) were decreased and anti-inflammatory cytokines (IL-10 and TGF-ß) were increased. In addition, we found that effective MSCs homing to the inflamed colon tissue occurred without long-term toxicity response. However, COX-2 inhibitor could diminish the therapeutic effects of MSCs. Using MSCs and macrophages co-culture system, we identified that MSCs could alleviate HAEC by inhibiting M1 macrophages activation through COX-2-dependent MAPK/ERK signaling pathway. CONCLUSIONS: MSCs ameliorate HAEC by reducing M1 macrophages polarization via COX-2 mediated MAPK/ERK signaling pathway, thus providing novel insights and potentially promising strategy for the treatment or prevention of HAEC.

3.
Fetal Pediatr Pathol ; 42(1): 123-130, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35403555

RESUMO

Inflammatory myofibroblastic tumor (IMT) infrequently involves the sigmoid colon, and has not previously been described in an infant sigmoid colon.An inflammatory myofibroblastic tumor arose from the sigmoid colon of an 11-month-old boy, confirmed by anaplastic lymphoma kinase (ALK), smooth muscle actin (SMA) and desmin immunohistochemical staining. The patient recovered well after complete resection of the tumor.Sigmoid IMT can occur in infancy. This eighth case is the youngest so far. The child did well after surgical resection.


Assuntos
Neoplasias de Tecido Muscular , Neoplasias do Colo Sigmoide , Masculino , Criança , Humanos , Lactente , Colo Sigmoide/patologia , Neoplasias do Colo Sigmoide/diagnóstico , Neoplasias do Colo Sigmoide/cirurgia , Neoplasias de Tecido Muscular/diagnóstico , Neoplasias de Tecido Muscular/cirurgia , Neoplasias de Tecido Muscular/patologia , Inflamação/patologia
4.
Front Surg ; 9: 996455, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36386515

RESUMO

Purpose: Radical surgery is the most effective treatment for Hirschsprung's disease. However, some children still have symptoms of intestinal dysfunction such as constipation, abdominal distension, and recurrent enterocolitis after operation. The purpose of this study was to evaluate treatment outcomes of postoperative intestinal dysfunction in children with Hirschsprung's disease by using the principle of "anorectal balance". Methods: The clinical data of postoperative intestinal dysfunction in children with Hirschsprung's disease in the single treatment group from July 2019 to July 2021 were retrospectively analyzed. All the enrolled children underwent botulinum toxin injection (2.5 U/kg); 3 to 6 months later, the injection was performed again; the children who had received more than two botulinum toxin injections underwent the internal sphincter myectomy. Anorectal manometry was performed routinely after operation, and abdominal distension and defecation were recorded. Results: A total of thirty children with postoperative intestinal dysfunction underwent radical surgery for Hirschsprung's disease were included in this study. Symptoms of constipation, abdominal distension and enterocolitis were improved after botulinum toxin injections in most children compared to before surgery (P < 0.01). After re-injection of botulinum toxin in twelve children, the frequency of defecation increased, the anal resting pressure decreased, and the clinical symptoms were relieved again (P < 0.05). Eleven children underwent internal sphincter myectomy, and the symptoms of constipation, abdominal distension and enterocolitis were significantly improved after the operation (P < 0.01). Conclusion: Botulinum toxin injection and internal sphincter myectomy based on the principle of "anorectal balance" can effectively reduce the resting pressure of the anus and relieve intestinal dysfunction, and have satisfactory clinical effect.

5.
Pediatr Surg Int ; 38(9): 1263-1271, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35852594

RESUMO

BACKGROUND: Anastomotic leakage (AL) is one of the most perplexing complications that can occur following a radical operation to treat Hirschsprung disease (HSCR). The purpose of this study was to document our experience with anastomotic leakage following radical HSCR surgery to enhance therapeutic effect and prognosis. METHODS: Between January 2007 and April 2021, a retrospective study was conducted on 12 children who developed anastomotic leakage following radical surgery for HSCR. Medical records were analyzed to determine the clinical manifestations, primary surgical procedures, evaluation methods, surgical plans, and outcomes of the patients. To assess postoperative bowel function, the Rintala score was used. RESULTS: The Soave procedure was used as the primary surgical method in seven cases (58.3%), the Swenson procedure was used in four cases (33.3%), and the Rehbein procedure was used in one case (8.3%). Enterostomy (10, 83.3%) and conservative treatment (2, 16.7%) were performed when anastomotic leakage was diagnosed. Two patients who directly closed stoma without redoing pull-through both accepted enterostomy within 48 h. One female with anastomotic fistula who was closed leakage or fistula in situ had to endure lifelong stoma. Other patients who underwent redo pull-through procedures had normal bowel function. Seven patients underwent a redo pull-through procedure. Three of them preferred the transanal full-thickness pull-through (FTPT) approach, while four preferred the Soave technique. Three children had mild postoperative soiling, which improved with conservative treatment. Bowel function score was 17.5 ± 1.1. CONCLUSION: Enterostomy should be performed immediately if anastomotic leakage occurs. After leakage, it is necessary to redo the pull-through procedure in an anastomotic fistula or anastomotic stricture. Transanal FTPT reconstruction is an effective method for repairing anastomoses and leakage.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Doença de Hirschsprung , Fístula Anastomótica/etiologia , Fístula Anastomótica/cirurgia , Criança , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Doença de Hirschsprung/complicações , Doença de Hirschsprung/cirurgia , Humanos , Lactente , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
6.
Org Lett ; 24(8): 1716-1721, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35199515

RESUMO

Tetraphenylporphyriyne (Pyne1), a novel porphyrin analogue with a C≡C bond incorporated into an 18-π-conjugated system, has been created via cleavage of the N-confused pyrrolic ring in Ag(III) N-confused tetraphenylporphyrin. The structure of Pyne1 was confirmed by X-ray crystallography and 1H NMR, IR, and UV-vis spectroscopy. The mechanism of cleavage of the N-confused pyrrolic ring was investigated by theoretical calculations. The successful synthesis of other Pynes indicated the generality of this protocol.

7.
Mol Med Rep ; 23(2)2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33355367

RESUMO

Recent studies have reported that aberrant PR domain zinc finger protein 14 (PRDM14) expression is associated with the therapeutic sensitivity of cancer cells to drugs. However, its role in lung adenocarcinoma (LUAD) remains unclear. The present study aimed to determine the functions of knockdown or overexpression of PRDM14 in the chemosensitivity and glycolysis of LUAD cells. PRDM14 expression was analyzed in lung cancer tissues from patients resistant and sensitive to cisplatin (DDP), as well as in LUAD cell lines A549 and DDP­resistant A549 (A549/DDP) using reverse transcription quantitative­PCR and western blotting. Additionally, apoptosis was analyzed by flow cytometry, and flow cytometry and biochemical analysis was used to analyze glycolysis, indicated by glucose uptake and lactate release. The results of the present study demonstrated that PRDM14 expression was upregulated in patients with DDP­resistant LUAD and DDP­resistant cell lines. Overexpression of PRDM14 suppressed the sensitivity of A549 cells to DDP and silencing of PRDM14 using shRNA targeting PRDM14 promoted the sensitivity of A549/DDP cells to DDP, compared with that in the respective control groups. In mice with xenograft tumors, knockdown of PRDM14 using shRNA targeting PRDM14 inhibited the A549/DDP cell­derived tumor growth compared with scramble shRNA. The results of the glycolysis assays demonstrated that PRDM14 silencing inhibited glucose uptake, lactate release and glucose transporter 1 expression in A549/DDP cells compared with those in the control cells. PRDM14 overexpression relieved the inhibitory effects of 3­bromopyruvate, a potent glycolytic inhibitor for glycolysis, on glucose uptake and lactate release in A549 cells compared with those in the control cells. Therefore, the results of the present study suggested that PRDM14 may inhibit the chemosensitivity and promote glycolysis in human LUAD cells.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Cisplatino/farmacologia , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Glicólise , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo , Células A549 , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Proteínas de Ligação a DNA/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas de Neoplasias/genética , Células-Tronco Neoplásicas/patologia , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética
8.
Artigo em Inglês | MEDLINE | ID: mdl-33204283

RESUMO

OBJECTIVE: To evaluate the evidence for the efficacy and safety of acupuncture at Tianshu (ST25) for functional constipation (FC). METHODS: We systematically searched seven databases to identify randomized controlled trials of acupuncture at ST25 alone or in combination with conventional therapy in the treatment of FC. Risk ratios (RRs) and mean differences (MDs) were calculated using RevMan 5.3 with 95% confidence interval (CI). RESULTS: The study included ten trials with 1568 participants. Meta-analysis showed that the Cleveland Constipation Score (CCS) for deep needling was significantly lower than that for lactulose (deep needling with low-frequency dilatational wave: MD -0.58, 95% CI -0.94 to -0.22; deep needling with sparse wave: MD -3.67, 95% CI -6.40 to -0.94; deep needling with high-frequency dilatational wave: MD -3.42, 95% CI -5.03 to -1.81). Furthermore, CCS for shallow needling with high-frequency dilatational wave was lower than that for lactulose (MD -1.77, 95% CI -3.40 to -0.14). In addition, when deep needling was combined with high-frequency dilatational wave, the weekly frequency of spontaneous defecation (FSD) was significantly higher than that for lactulose (MD 1.57, 95% CI 0.93 to 2.21). Colonic Transit Time (CTT) scores were significantly higher when deep needling was combined with sparse wave (MD -14.36, 95% CI -18.31 to -10.41) or high-frequency dilatational wave (MD -11.53, 95% CI -19.25 to -3.81). The time of first defecation after treatment (TFD) of the shallow needling therapy was significantly longer than that of the lactulose (MD 13.67, 95% CI 5.66 to 21.67). The CCS 6 months after treatment (CCS6m) for deep needling was significantly lower than that for lactulose (MD -4.90, 95% CI -5.97 to -3.84). Moreover, the FSD 6 months after treatment (FSD6m) for shallow needling was significantly higher than that for lactulose (MD 0.49, 95% CI 0.02 to 0.97). The adverse event (AE) rate for lactulose was significantly higher than that achieved with the needling treatments, and this held true for both deep needling therapy (RR 0.41, 95% CI 0.23 to 0.72) and shallow needling therapy (RR 0.33, 95% CI 0.15 to 0.77). CONCLUSIONS: The meta-analysis demonstrates that acupuncture at ST25 appears to be more effective than lactulose in the treatment of functional constipation. This was found to be especially true for deep needling with high-frequency dilatational wave, which had a greater impact on improving CCS, FSD, CTT, and CCS6m. Additionally, acupuncture at ST25 was shown to be safer than conventional treatment, with the rate of AE being significantly lower for both deep needling and shallow needling. The trial is registered with https://www.crd.york.ac.uk/prospero/(CRD42019141017)).

9.
J Phys Chem A ; 124(24): 5033-5041, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32436382

RESUMO

To provide feasible methods for the extraction of valuable metals from spent batteries or low-grade primary ores, the extraction behavior of some representative acidic phosphorus-containing compounds (APCCs) as extractants is evaluated from the perspective of experimental and theoretical investigations in this work. Aqueous solutions containing five metal ions, Ca(II), Co(II), Mg(II), Mn(II), and Ni(II), were made to simulate leaching liquids, and the extraction of these metals was investigated. A simplified calculated model was used to evaluate the interaction between each extractant and metal ions. The calculation results agree well with the experimental tests in trend. This work not only provides potential extractants for the extraction of valuable metals from spent batteries or low-grade primary ores but also demonstrates the practicability of the simplified calculation model.

10.
Org Lett ; 22(6): 2281-2286, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32115957

RESUMO

We report herein a general and practical copper-catalyzed fluorosulfonylation reaction of a wide range of abundant arenediazonium salts to smoothly prepare various arenesulfonyl fluorides using the 1,4-diazabicyclo[2.2.2]octane-bis(sulfur dioxide) adduct as a convenient sulfonyl source in combination with KHF2 as an ideal fluorine source and without the need for additional oxidants. Interestingly, the electronic character of the arene ring in the starting arenediazonium salts has a significant impact on the reaction mechanistic pathway.

11.
Phys Chem Chem Phys ; 22(8): 4715-4730, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32057037

RESUMO

Benziporphyrins are versatile macrocycles exhibiting aromaticity switching behaviors. The existence of both Hückel and Möbius (anti)aromaticity has been reported in these systems, whose validity is respectively governed by the [4n + 2] and [4n] π-electron rule on the macrocyclic pathway. Despite the experimental evidence on the floppiness of benziporphyrins, the switching mechanism between Hückel and Möbius structures is still not clear, as well as the factors influencing the stability of the different π-conjugation topologies. For these reasons, we performed a systematic study on A,D-di-p-benzihexaphyrins(1.1.1.1.1.1) with two redox states corresponding to [28] and [30] π-electron conjugation pathways. Whereas benzi[28]hexaphyrin obeys Möbius aromaticity, benzi[30]hexaphyrin follows Hückel aromaticity. The dynamic interconversion between Möbius and Hückel aromaticity is investigated through the rotation of a phenylene ring, which acts as the topology selector. Further analyses of the energy profiles using energy decomposition and information-theoretic approaches provide new insights into conformational stability, aromaticity and antiaromaticity for these species. Strong and opposite cross correlations between aromaticity indexes and information-theoretic quantities were found for the two macrocyclic systems with opposite global aromaticity and antiaromaticity behaviors. These results indicate that Hückel and Möbius aromaticity and antiaromaticity, though qualitatively different, are closely related and can be interchanged, and information-theoretic quantities provide a novel understanding about their relevance. Our present results should provide in-depth insights to appreciate the nature and origin about Möbius (anti)aromaticity and its close relationship with Hückel (anti)aromaticity.

12.
Nat Commun ; 10(1): 5362, 2019 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-31767850

RESUMO

As a versatile intermediate, difluorocarbene is an electron-deficient transient species, meaning that its oxidation would be challenging. Herein we show that the oxidation of difluorocarbene could occur smoothly to generate carbonyl fluoride. The oxidation process is confirmed by successful trifluoromethoxylation, 18O-trifluoromethoxylation, the observation of AgOCF3 species, and DFT calculations.

13.
Phys Chem Chem Phys ; 21(33): 18195-18210, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31389933

RESUMO

In this work, we report a systematic study on the global and local aromaticity of acenes using a series of model structures from 2-acene to 11-acene. A recently developed ansatz, an information-theoretic approach coached into density functional reactivity theory has been employed, which essentially provides different density functionals characterizing the molecular electron density distribution. Based on the correlation analysis of six conventional aromaticity indices with eight information-theoretic quantities, we examined the aromaticity of acenes from both global and local perspectives. From the global aromaticity viewpoint, our results suggest that different descriptors based on various physicochemical properties are intrinsically dependent. A novel laminated feature ruling local aromaticity of acenes has been unveiled, from which we found that the distance from the terminal rings plays the critical role. Based on the shape of the correlation plots between the conventional aromaticity indices and information-theoretic quantities, the latter could be separated into three subgroups. The seemingly contradictory results from global and local aromaticity perspectives not only present us the uniqueness of the acene systems but all demonstrate the effectiveness of the information-theoretic approach from density functional reactivity theory. Besides strengthening the validity of a series of new aromaticity descriptors, our results should lead to more clear insights into the chemical significance of the information-theoretic quantities.

14.
J Phys Chem A ; 123(31): 6751-6760, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31305075

RESUMO

The oxidation state, also called oxidation number, of atoms in molecules is a fundamental chemical concept. It is defined as the charge of an atom in a molecule after the ionic approximation of its heteronuclear bonds is applied. Even though for simple molecules the assignment of oxidation states is straightforward, redundancy and ambiguity do exist for others. In this work, we present a density-based framework to determine the oxidation state using the quantities from the information-theoretic approach. As a proof of concept, we examined six elements for a total of 49 molecules. Strong linear correlations were obtained with Shannon entropy, Ghosh-Berkowitz-Parr entropy, information gain, relative Rényi entropy of orders 2 and 3, and Hirshfeld charge. We also discovered that the crystal radius of elements plays the key role in rationalizing the system dependent nature of these strong linear correlations. The validity and effectiveness of our results were demonstrated by the examples of molecules containing elements with two or more oxidation states. Our results should be applicable to more complicated systems in assigning different oxidation states.

15.
J Phys Chem Lett ; 10(8): 1716-1721, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30916572

RESUMO

Molecular systems bound together through noncovalent interactions are ubiquitous in nature, many of which are involved in essential life processes, yet little is known about the principles governing their structure, stability, and function. Cooperativity as one of the intrinsic properties in these systems plays a key role. In this work, on the basis of our recent quantification scheme of the cooperativity effect, we present a general pattern to identify which systems are positively cooperative and which are negatively cooperative. We show that cooperativity in homogeneous molecular systems is positive, but cooperativity in charged molecular systems is negative. We also employ analytical tools from energetics and information perspectives to appreciate the origin of the cooperativity effect. We find that positive cooperativity is dominated by the exchange-correlation interaction and steric effect, whereas negative cooperativity is governed by the electrostatic interaction. Our results should have strong implications for better understanding molecular recognition, protein folding, signal transduction, allosteric regulation, and other processes.

16.
ACS Biomater Sci Eng ; 5(9): 4331-4340, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-33417789

RESUMO

Hydrophobic coating is of great interest to enhance the corrosion resistance of magnesium alloy implants, which always suffer from rapid corrosion that leads to the failing application under physiological conditions. Plasma-polymerized fluorocarbon (C-F) coating has been widely studied as a substrate protection layer; however, the precise control of the deposition rate of C-F coating with fluorinated alkanes has been a challenge. In this study, a thin, uniform, pinhole-free, polymerlike, and hydrophobic C-F coating was successfully prepared using acetylene (C2H2) as a cross-linking agent, which endows the coating with tunable properties of deposition rate by incorporation of unsaturated bonds. Electrochemical corrosion and in vitro immersion test demonstrated that the C-F coating significantly slows down the corrosion rate of MgZnMn in phosphate-buffered saline solution at 37 °C. Furthermore, an additional layer of PPAam was deposited on the C-F coating to eliminate the adverse effect of C-F surface on cytocompatibility. Thus, such a stacked coating imparts MgZnMn with a significantly improved corrosion resistance and promotes cell adhesion and viability. Therefore, the strategy of acetylene-mediated C-F-based coating shows a great potential for tailoring ideal surface functionalities of magnesium-based medical devices.

17.
J Am Chem Soc ; 140(48): 16553-16559, 2018 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-30421611

RESUMO

All-aza smaragdyrin, a historic but elusive pentapyrrolic macrocycle, was successfully synthesized and characterized for the first time. [22]Smaragdyrin BF2-complex 3 was smoothly synthesized by 2-fold SNAr reaction of 1,9-dibromo-5-mesityldipyrrin with 5,10-dimesityltripyrrane. Treatment of 3 with methanesulfonic acid gave [20]smaragdyrin 5 as a stable antiaromatic compound. Reduction of 5 with NaBH4 under inert conditions gave [22]smaragdyrin 6 as an aromatic congener, which was easily oxidized back to 5 in the air. Complex 3 was interconvertible with its 20π-congener 4 via oxidation with MnO2 and reduction with NaBH4. Treatment of 3 or 4 with CuCl2 in the presence of NaOAc gave hetero bimetal complex 8.

18.
Pediatr Surg Int ; 34(8): 897-901, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29872885

RESUMO

Congenital biliary dilatation (CBD) is usually associated with complications such as recurrent cholangitis, manifested as abdominal pain, vomiting, and jaundice. If cholangitis cannot be controlled by conservative treatment, a good therapeutic effect can be obtained through percutaneous biliary drainage or open T-tube drainage. We aimed to evaluate our experiences in biliary drainage through endoscopic retrograde cholangiopancreatography in children with cholangitis caused by CBD. From January 2014 to December 2017, 167 children with CBD were treated in our hospital. 17 patients (10.18%) with serious cholangitis caused by CBD underwent ERCP. There were 4 males and 13 females with an age range of 10-120 months (average 56.4 months). Placement of a biliary stent was attempted for biliary drainage through endoscopic retrograde cholangiopancreatography. Of the 17 patients studied, 13 children had jaundice and 15 had elevated aminotransferases. ERCP showed CBD in all patients and a common biliopancreatic duct in 12 of 17 patients (70.6%). Five patients underwent nasobiliary drainage and 12 patients underwent biliary drainage through double pigtail tubes. All patients achieved successful biliary drainage. Postoperative pancreatitis occurred in one patient. Biochemical indicators decreased significantly in 12 patients (70.6%) on the second postoperative day. The average length of hospital stay after surgery was 4.5 (range 3-7) days. No major complications related to ERCP were observed and all children had a good prognosis so far. Endoscopic biliary drainage is a safe, simple, and reliable technique. It can be used to resolve CBD-associated cholangitis, evaluate the biliary tract and pancreatobiliary duct junction, and guide pediatric surgeons to choose the right time and the correct procedure for CBD.


Assuntos
Doenças Biliares/complicações , Colangite/terapia , Dilatação Patológica/complicações , Drenagem/métodos , Endoscopia do Sistema Digestório , Doenças Biliares/congênito , Pré-Escolar , Colangiopancreatografia Retrógrada Endoscópica , Colangite/etiologia , Dilatação Patológica/congênito , Feminino , Humanos , Lactente , Masculino
19.
Phys Chem Chem Phys ; 20(26): 17990-17998, 2018 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-29927447

RESUMO

Cooperativity is a widely used chemical concept whose existence is ubiquitous in chemical and biological systems but whose quantification is still controversial and origin much less appreciated. In this work, using the interaction energy of a molecular system, which is composed of multiple copies of a building block, we propose a quantitative measurement to evaluate the cooperativity effect. This quantification approach is then applied to six molecular systems, i.e., water cluster, argon cluster, protonated water cluster, zinc atom cluster, water cluster on top of a graphene sheet, and alpha helix of glycine amino acids, each with up to 20 copies of the building block. Cooperativity is seen in all these systems. Both positive and negative cooperativity effects are observed. Employing the two energy partition schemes in density functional theory and the information-theoretic quantities such as Shannon entropy, Fisher information, information gain, etc., we then examine the origin of the cooperativity effect for these systems. Strong linear correlations between the cooperativity measure and some of these theoretical quantities have been unveiled. With these correlations, we are able to quantitatively account for their origin of cooperativity. Our results show that the interactions governing the existence and validity of the cooperativity effect are complicated. An opposite mechanism in enthalpy-entropy compensation for positive and negative cooperativity has been unveiled. These results should provide new insights and understandings from a different viewpoint about the nature and origin of cooperativity to appreciate this vastly important chemical concept.

20.
Phys Chem Chem Phys ; 20(3): 1408-1420, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29299564

RESUMO

The steric effect is one of the most widely used chemical concepts in chemistry, yet a generally accepted implementation of its formulation and quantification from a theoretical viewpoint, if even possible, is still an unaccomplished task. Based on the energetics viewpoint of our earlier proposal using the Weizsäcker kinetic energy as a quantification of the energy contribution from the steric effect as well as our recent work using steric force as a reliable local descriptor to account for the origin of the stereoselective propensity in chemical reactions, in this work, we systematically examine the local behavior and general applicability of another closely related quantity, steric charge. To this end, its physical origin and physiochemical properties are formalized and highlighted, and are shown with numerical illustrations and verifications. To showcase its usefulness in appreciating chemical reactivity, we present three case studies of steric charge in this work. In the case of ethane flexible rotation, we found that the eclipsed conformer is more sterically charged than the staggered conformer, leading to the reduced stability and higher energy of the former. For the case of SN2 reactions, a remarkable linear correlation has been obtained between the steric charge on the central atom in the transition state and the reaction barrier height of SN2 reactions, in good agreement with experimental findings. In the case of stereoselectivity properties for the nucleophilic addition of carbonyl compounds, we found that steric charge is equally applicable as steric force to justify the stereoselective origin for the nucleophilic attack to the carbonyl carbon atom with different substituent groups. Put together, our results from the present study should pave the way towards the general use of steric charge, together with steric energy and steric force, as an insightful global and local descriptor to appreciate and quantify chirality and stereoselectivity related phenomena in chemical processes and transformations.

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