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Risk Factors of Perioperative Brain Injury in Children Under Two Years Undergoing Coarctation Repair. Pediatr Neurol 2023; 141:109-117. [PMID: 36812697 DOI: 10.1016/j.pediatrneurol.2023.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 01/10/2023] [Accepted: 01/14/2023] [Indexed: 01/22/2023]
Abstract
BACKGROUND To investigate clinical manifestations and factors of perioperative brain injury (PBI) after surgical repair of coarctation of the aorta (CoA) combined with other heart malformations under cardiopulmonary bypass (CPB) in children under two years. METHODS The clinical data of 100 children undergoing CoA repair were retrospectively reviewed between January 2010 and September 2021. Univariate and multivariate analyses were performed to identify factors of PBI development. Hierarchical and K-means cluster analyses were conducted to evaluate the association between hemodynamic instability and PBI. RESULTS Eight children developed postoperative complications, and all of them had a favorable neurological outcome one year after surgery. Univariate analysis revealed eight risk factors associated with PBI. Multivariate analysis indicated operation duration (P = 0.04, odds ratio [OR], 2.93; 95% confidence interval [CI], 1.04 to 8.28) and pulse pressure (PP) minimum (P = 0.01; OR, 0.22; 95% CI, 0.06 to 0.76) were independently associated with PBI. The following three parameters emerged for cluster analysis: PP minimum, mean arterial pressure (MAP) dispersion, and systemic vascular resistance (SVR) average. Using cluster analysis, PBI mainly occurred in subgroups 1 (12%, three of 26) and 2 (10%, five of 48). The mean value of PP and MAP in subgroup 1 was significantly higher than in subgroup 2. The mean SVR in subgroup 1 was the highest. The lowest PP minimum, MAP, and SVR were observed in subgroup 2. CONCLUSION Lower PP minimum and longer operation duration were independent risk factors for developing PBI in children under two years during CoA repair. Unstable hemodynamics should be avoided during CPB.
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Developmental characteristics of visual evoked potentials to different stimulation in normal children. Int J Neurosci 2023; 133:296-306. [PMID: 33843429 DOI: 10.1080/00207454.2021.1912039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To determine the developmental characteristics of flash visual evoked potentials (FVEP) and pattern-reversal visual evoked potentials (PVEP) of healthy children. METHODS The data were collected with a Keypoint Workstation 9033A07; 168 children (2 months-13 years) were tested with FVEP and 101 (4-13 years) were tested with PVEP. RESULTS A triphasic waveform with clear components (N2, P2, and N3) was recorded steadily after 1 year, with occurrence rates over 97% at all frequencies. FVEP latency significantly decreased with age. The amplitude difference of FVEP was greater for binocular than monocular fields. FVEP amplitude increased and amplitude differences decreased with stimulation frequency. The occurrence rate of PVEP was 100% after 4 years, and PVEP latency was significantly prolonged with age. N75 and P100 amplitudes and the N75-P100 amplitude difference increased with field of vision. CONCLUSION FVEP can be evoked in normal children at less than 2 Hz. Stimulation frequency can be adjusted to improve early detection and verification of subclinical lesions. The PVEP waveform is simple and stable, and its results are easier to analyze and interpret than FVEP, but it is limited by visual acuity and fixation force, whereas FVEP is affected less by visual acuity. but it is necessary to establish normal reference values of each age in each laboratory because of complicated analysis. According to the specific situation of the patient (vision, fixation) and clinical demand, we need to choose the right stimulation.
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A Nomogram to Predict Bacterial Meningitis-associated Hydrocephalus: A Single-Center Retrospective Study. Pediatr Infect Dis J 2022; 41:706-713. [PMID: 35622426 DOI: 10.1097/inf.0000000000003590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE We aimed to develop a predictive nomogram for the early detection of hydrocephalus in children with bacterial meningitis. METHODS This retrospective study was based on data of children with bacterial meningitis admitted to our hospital between January 2016 and December 2020. Risk factors were evaluated using univariate analysis, and the predictive model/nomogram was built using binary logistic analysis. A nomogram calibration plot, Hosmer-Lemeshow test and receiver operating characteristic (ROC) curve evaluated the predictive performance. Ordinary bootstrapping processed the internal validation. RESULTS We enrolled 283 patients who matched the inclusion criteria, among whom 41 cases (14.49%) had confirmed bacterial meningitis-associated hydrocephalus (BMAH). The incidence of sequelae in the patients with BMAH was 88.9% (24/27), which was significantly higher than that in the patients without BMAH. Univariate regression analysis revealed that 14 clinical indicators were associated with BMAH. Multivariate analysis identified 4 variables as independent risk factors to establish the predictive model: repeated seizures, loss of consciousness, procalcitonin ≥7.5 ng/dL and mechanical ventilation. And a graphical nomogram was designed. The area under the ROC curve was 0.910. In the Hosmer-Lemeshow test the P value was 0.610. The mean absolute error in the calibration plot was 0.02. Internal validation showed the testing set was in good accordance with the original set when internal validation was performed. CONCLUSIONS The predictive model/nomogram of BMAH could be used by clinicians to determine hydrocephalus risk.
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[Application of island flap and its combined flap on repairing nasal alae defects]. ZHONGHUA ER BI YAN HOU TOU JING WAI KE ZA ZHI = CHINESE JOURNAL OF OTORHINOLARYNGOLOGY HEAD AND NECK SURGERY 2021; 56:1174-1178. [PMID: 34749456 DOI: 10.3760/cma.j.cn115330-20210529-00303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To evaluate the application of island flap and combined flap in one-stage reconstruction of nasal alae defects after external nasal tumor resection. Methods: Data of 11 patients with perforating or full-thickness defects of the alae after nasal tumor resection in XuanWu Hospital, Capital Medical University between June 2016 and February 2021 were analyzed retrospectively. There were 7 males and 4 females, and the ages ranged from 51 to 89 years. Island flap, island flap combined with nasolabial flap or V-Y advancement flap, and island flap combined with bilobed flap were applied according to the range of defects. Descriptive statistical method was applied to analyze the treatment effects. Results: All flaps of the 11 patients were successful survival and the incisions were primary healing. Being followed up for 5 to 59 months, the patients had satisfying appearance and ventilation function, and no tumor relapsed. Conclusion: For the patients with nasal alae defects after external nose tumor resection, selecting suitable island skin flap or combined skin flap can be used to reconstruct the ideal nasal appearance and function of the nose.
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Synergistic effects of α-Fe 2O 3nanoparticles and Fe-doping on gas-sensing performance of NiO nanowires and interface mechanism. NANOTECHNOLOGY 2021; 32:485502. [PMID: 34352739 DOI: 10.1088/1361-6528/ac1afb] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
High surface area nickel oxide nanowires (NiO NWs), Fe-doped NiO NWs andα-Fe2O3/Fe-doped NiO NWs were synthesized with nanocasting pathway, and then the morphology, microstructure and components of all samples were characterized with XRD, TEM, EDS, UV-vis spectra and nitrogen adsorption-desorption isotherms. Owing to the uniform mesoporous template, all samples with the same diameter exhibit the similar mesoporous-structures. The loadedα-Fe2O3nanoparticles should exist in mesoporous channels between Fe-doped NiO NWs to form heterogeneous contact at the interface of n-typeα-Fe2O3nanoparticles and p-type NiO NWs. The gas-sensing results indicate that Fe-dopant andα-Fe2O3-loading both improve the gas-sensing performance of NiO NWs sensors.α-Fe2O3/Fe-doped NiO NWs sensors presented the highest response to 100 ppm ethanol gas (55.264) compared with Fe-doped NiO NWs (24.617) and NiO NWs sensors (3.189). The donor Fe-dopant increases the ground state resistance and the absorbed oxygen content in air.α-Fe2O3nanoparticles in electron depletion region result in the increasing resistance in ethanol gas and decreasing resistance in air. In this way,α-Fe2O3/Fe-doped NiO NWs sensor presents the excellent gas-sensing performance due to the formation of heterogeneous contact at the interface.
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[A prospective cohort study on blood pressure control and risk of ischemic stroke in patients with hypertension]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2020; 54:737-741. [PMID: 32842295 DOI: 10.3760/cma.j.cn112150-20191225-00958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To explore the association between blood pressure control and risk of ischemic stroke (IS) in patients with hypertension. Methods: A total of 5 488 patients with hypertension from 60 communities were randomly selected from 101 communities in 8 streets of Nanshan District in Shenzhen City by using two-stage sampling method. The social demographic characteristics, behavior and life style, coronary heart disease and diabetes were collected and the physical condition, blood pressure and blood biochemical indexes were measured. From April 1, 2010 to August 31, 2017 as the follow-up period, the incidence of IS was annually collected by using telephone survey. Cox proportional hazard regression model was used to analyze the relationship between blood pressure control, systolic blood pressure (SBP), diastolic blood pressure (DBP) and the risk of IS. Results: The age of all patients was (58.50±12.14) years old, including 2 712 males (49.42%) and 3 112 patients with well-controlled blood pressure (56.71%). During the follow-up period, 358 new cases of IS were confirmed, and the incidence density was 1 346.27/100 000 person-years. Cox proportional hazard regression model analysis showed after adjusting for confounding factors, unstable blood pressure control, SBP≥150 mmHg (1 mmHg=0.133 kPa; compared with SBP<120 mmHg), and DBP≥95 mmHg (compared with DBP<80 mmHg) were associated with risk of IS. The HR (95%CI) was 1.29 (1.04, 1.59), 2.00 (1.26, 3.17) and 1.52 (1.01, 2.64), respectively. Subgroup analyses showed these associations only existed in female patients with hypertension. The HR (95%CI) was 1.39 (1.05, 1.85), 2.53 (1.41, 4.56) and 1.73 (1.00, 3.36), respectively. Conclusion: Unstable blood pressure control increases the risk of IS in female patients with hypertension.
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[Nephrogenic clear cell carcinoma of nasal cavity:a case report]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2019; 33:773-774. [PMID: 31446739 DOI: 10.13201/j.issn.1001-1781.2019.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Indexed: 11/12/2022]
Abstract
SummaryRenal clear cell carcinoma(RCCC) is the most common type of renal cell carcinoma, but metastasis to the nasal cavity is extremely rare. A case of RCCC to the nasal cavity and paranasal sinuses was reported. The early clinical manifestations of this case were intermittent epistaxis and subsequent massive epistaxis. Imaging examination revealed that there were masses in the nasal cavity and paranasal sinus, accompanied by bleeding and destruction of the skull base. Renal CT examination showed a tumor in the right kidney, and considered the patient suffering from renal cell carcinoma. The patient underwent a nasal side incision to remove the tumor, the patient's pathological return; nasal nephrogenic clear-cell carcinoma.
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Monitoring and assessment of heavy metal contamination in a constructed wetland in Shaoguan (Guangdong Province, China): bioaccumulation of Pb, Zn, Cu and Cd in aquatic and terrestrial components. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:9079-9088. [PMID: 27164879 DOI: 10.1007/s11356-016-6756-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 04/25/2016] [Indexed: 06/05/2023]
Abstract
The objective of this study is to evaluate the current status of heavy metal concentrations in constructed wetland, Shaoguan (Guangdong, China). Sediments, three wetland plants (Typha latifolia, Phragmites australis, and Cyperus malaccensis), and six freshwater fish species [Carassius auratus (Goldfish), Cirrhinus molitorella (Mud carp), Ctenopharyngodon idellus (Grass carp), Cyprinus carpio (Wild common carp), Nicholsicypris normalis (Mandarin fish), Sarcocheilichthys kiangsiensis (Minnows)] in a constructed wetland in Shaoguan were collected and analyzed for their heavy metal compositions. Levels of Pb, Zn, Cu, and Cd in sediments exceeded approximately 532, 285, 11, and 66 times of the Dutch Intervention value. From the current study, the concentrations of Pb and Zn in three plants were generally high, especially in root tissues. For fish, concentrations of all studied metals in whole body of N. mormalis were the highest among all the fishes investigated (Pb 113.4 mg/kg, dw; Zn 183.1 mg/kg, dw; Cu 19.41 mg/kg, dw; 0.846 mg/kg, dw). Heavy metal accumulation in different ecological compartments was analyzed by principle component analysis (PCA), and there is one majority of grouped heavy metals concentration as similar in composition of ecological compartment, with the Cd concentration quite dissimilar. In relation to future prospect, phytoremediation technology for enhanced heavy metal accumulation by constructed wetland is still in early stage and needs more attention in gene manipulation area.
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Expression analysis of differentially expressed miRNAs in male and female chicken embryos. GENETICS AND MOLECULAR RESEARCH 2014; 13:3060-8. [PMID: 24782163 DOI: 10.4238/2014.april.17.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
MicroRNAs (miRNAs) are small non-coding RNA molecules that play key roles in the regulation of development processes of many tissues and organs at the post-transcriptional level. However, little is known about how they affect chicken gonadal development. We examined the expression of four miRNAs (miR-218, -200b, -196, and -206) in chicken embryonic gonads at embryonic days 3.5-6.5. Their target genes were predicted by miRDB, TargetScan and PicTar algorithms. The expression levels of these four miRNAs differed with sex to varying degrees; miR-200b was expressed at a significantly higher level in female gonads during the entire interval. The whole mount in situ hybridization result showed considerably higher expression of miR-200b in females than in males in E5.5 embryos. The miRNA target scanning results indicated several genes with functions in gonad development and gonad function. We conclude that miR-200b is involved in the regulation of gonad development and sexual differentiation of chicken embryos.
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Adsorption kinetics of Pb and Cd by two plant growth promoting rhizobacteria. BIORESOURCE TECHNOLOGY 2009; 100:4559-4563. [PMID: 19447032 DOI: 10.1016/j.biortech.2009.04.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 04/09/2009] [Accepted: 04/19/2009] [Indexed: 05/27/2023]
Abstract
A bench study was carried out to characterize the kinetics of two plant growth promoting rhizobacteria (PGPR) Azotobacter chroococcum and Bacillus megaterium to adsorb heavy metals from solution. Adsorption of Pb(2+) and Cd(2+) by bacterial cells was processed quickly with an equilibration achieved within 5 min. The adsorptions were fitted well with Freundlich and Langmuir isotherm models. The comparison of isotherm parameters indicated that A. chroococcum had a stronger capacity to bind metal ions than B. megaterium, with an average increase of 59.8% for Pb(2+) and 75.6% for Cd(2+), respectively. Both bacteria had a stronger affinity to Pb(2+) than Cd(2+) since Pb(2+) was more easily bound with the phosphoryl groups on the cell surface than Cd(2+). This demonstrated that the presence of bacteria in the rhizosphere may result in the reduction of mobile ions in soil solution.
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Stockholm Convention organochlorine pesticides and polycyclic aromatic hydrocarbons in Hong Kong air. CHEMOSPHERE 2009; 77:714-719. [PMID: 19775721 DOI: 10.1016/j.chemosphere.2009.08.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 08/19/2009] [Accepted: 08/22/2009] [Indexed: 05/28/2023]
Abstract
Organochlorine pesticides (OCPs) including eight of the original nine pesticides listed in the Stockholm Convention on Persistent Organic Pollutants, and polycyclic aromatic hydrocarbons (PAHs) were measured in 90 air samples collected from January 2004 to March 2005, and in 304 air samples collected from January 1998 to December 2005 in Hong Kong, respectively. The annual average OCP concentrations at Tap Mun, Yuen Long and Tsuen Wan were 135+/-140 (ND-482), 186+/-183 (ND-656), and 190+/-239 fg m(-3) (ND-966), respectively, while annual (January 1998 to December 2005) average concentrations of total PAHs at Tsuen Wan, and Central/Western were 578+/-261 (117-938) and 588+/-248ngm(-3) (103-874), respectively. No seasonal and spatial variations in OCP concentrations were observed due to trace levels, and estimation of carcinogenic risks of OC pesticides was low. Naphthalene (>70%) was the dominant PAH in terms of concentrations measured. The sum of three-ring PAHs, including acenaphthene, acenaphthylene, anthracene, fluorene and phenanthrene, contributed to around 20% of the total PAH concentration while the contribution of heavier PAHs (sum of four-, five- and six-rings) was less than 5%. t-Values of the paired samples T-test for the individual PAHs showed that the concentrations of benzo(a)pyrene, the relative high cancer risk PAH, and most of the PAHs detected at Tsuen Wan and Central/Western were significantly different (p<0.01), with higher concentrations detected at Tsuen Wan. Several PAHs exhibited strong seasonality with higher concentrations in winter. Sources of PAHs were determined by investigating PAH isomer ratios which suggested petrogenic sources as primary sources of PAHs in Hong Kong air.
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Identification of mutations of zona pellucida glycoprotein (ZP3) and its association with pig reproductive traits. J Anim Breed Genet 2007; 124:144-9. [PMID: 17550356 DOI: 10.1111/j.1439-0388.2007.00651.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reproduction is a complex trait, controlled by genetic and environmental factors. Genetic improvement of this trait is important for animal breeders to improve the animal's production efficiency. Apart from genetic factors, animal production can be affected by environmental factors, i.e. the nursing ability of the sow, which is in turn affected directly by effective teat number (teats producing milk normally, TN) and number of piglets born alive (NBA). The objective of this study was to find new mutations, such as single nucleotide polymorphisms (SNPs) from the Zona Pellucida glycoprotein gene (ZP3) using Single Strand Chain Polymorphism (SSCP) and nucleotide sequencing and to investigate association between genetic variations and sow reproductive traits. We identified 13 new SNPs from exon 1, two new SNPs from intron 2, one SNP from intron 6 and a 18 bp (GCACGTGGTCCTCCTGG)-deletion/insertion from intron 2 of the ZP3 gene. Five out of these mutations were selected to genotype in five different breeds (Small Meishan, Qingping, Duroc, Landrace and Large White) and association with reproductive traits in European breeds (Duroc, Landrace and Large White). The sows with genotype AA had more 1.11 piglets NBA than of the sows with genotype AB (p < 0.05) in the 18 bp deletion/insertion of intron 2, while non-significant associations between the other mutations and reproductive traits (NBA and TN) were found.
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The application of Kriging and empirical Kriging based on the variables selected by SCAD. Anal Chim Acta 2006; 578:178-85. [PMID: 17723710 DOI: 10.1016/j.aca.2006.06.073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 04/28/2006] [Accepted: 06/26/2006] [Indexed: 10/24/2022]
Abstract
The commonly used approach for building a structure-activity/property relationship consists of three steps. First, one determines the descriptors for the molecular structure, then builds a metamodel by using some proper mathematical methods, and finally evaluates the meta-model. Some existing methods only can select important variables from the candidates, while most metamodels just explore linear relationships between inputs and outputs. Some techniques are useful to build more complicated relationship, but they may not be able to select important variables from a large number of variables. In this paper, we propose to screen important variables by the smoothly clipped absolute deviation (SCAD) variable selection procedure, and then apply Kriging model and empirical Kriging model for quantitative structure-activity/property relationship (QSAR/QSPR) research based on the selected important variables. We demonstrate the proposed procedure retains the virtues of both variable selection and Kriging model.
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Impersonality of the connectivity index and recomposition of topological indices according to different properties. Molecules 2004; 9:1089-99. [PMID: 18007506 DOI: 10.3390/91201089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 12/07/2004] [Accepted: 12/08/2004] [Indexed: 11/16/2022] Open
Abstract
The connectivity index chi can be regarded as the sum of bond contributions. In this article, boiling point (bp)-oriented contributions for each kind of bond are obtained by decomposing the connectivity indices into ten connectivity character bases and then doing a linear regression between bps and the bases. From the comparison of bp-oriented contributions with the contributions assigned by chi, it can be found that they are very similar in percentage, i.e. the relative importance of each particular kind of bond is nearly the same in the two forms of combinations (one is obtained from the regression with boiling point, and the other is decided by the constructor of the chi index). This coincidence shows an impersonality of chi on bond weighting and may provide us another interpretation of the efficiency of the connectivity index on many quantitative structure-activity/property relationship (QSAR or QSPR) results. However, we also found that chi's weighting formula may not be appropriate for some other properties. In fact, there is no universal weighting formula appropriate for all properties/activities. Recomposition of some topological indices by adjusting the weights upon character bases according to different properties/activities is suggested. This idea of recomposition is applied to the first Zagreb group index M(1) and a large improvement has been achieved.
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Structural Interpretation of the Topological Index. 2. The Molecular Connectivity Index, the Kappa Index, and the Atom-type E-State Index. ACTA ACUST UNITED AC 2004; 44:1193-201. [PMID: 15272826 DOI: 10.1021/ci049973z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structural interpretation is extended to the topological indices describing cyclic structures. Three representatives of the topological index, such as the molecular connectivity index, the Kappa index, and the atom-type E-State index, are interpreted by mining out, through projection pursuit combining with a number theory method generating uniformly distributed directions on unit sphere, the structural features hidden in the spaces spanned by the three series of indices individually. Some interesting results, which can hardly be found by individual index, are obtained from the multidimensional spaces by several topological indices. The results support quantitatively the former studies on the topological indices, and some new insights are obtained during the analysis. The combinations of several molecular connectivity indices describe mainly three general categories of molecular structure information, which include degree of branching, size, and degree of cyclicity. The cyclicity can also be coded by the combination of chi cluster and path/cluster indices. The Kappa shape indices encode, in combination, significant information on size, the degree of cyclicity, and the degree of centralization/separation in branching. The size, branch number, and cyclicity information has also been mined out to interpret atom-type E-State indices. The structural feature such as the number of quaternary atoms is searched out to be an important factor. The results indicate that the collinearity might be a serious problem in the applications of the topological indices.
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Structural Interpretation of a Topological Index. 1. External Factor Variable Connectivity Index (EFVCI). ACTA ACUST UNITED AC 2004; 44:437-46. [PMID: 15032523 DOI: 10.1021/ci034225f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The external factor variable connectivity index (EFVCI) is interpreted by mining out the structural features hidden in the space spanned by the EFVCI indices through projection pursuit combining with number-theory net (NT-net) on the unit sphere U(Us). Projection pursuit is concerned with "interesting" projections of high-dimensional data sets to machine-pick "interesting" low-dimensional projections of a high-dimensional point cloud by numerically maximizing a certain objective function or projection index. At first, the optimal EFVCI index reaches to -0.80 in the correlation with a retention index of 207 hydrocarbons produced by insects. The EFVCI indices, with regression results of R = 0.99998, s = 3.49, RMSECV = 3.90, and F = 7.9560e+005, obtain high regression quality. The model is proven valid by leave-one-out cross validation. Second, the EFVCI index is interpreted by the structure information, that is, size, branch number, graph center, and branching position of topological structures, which is searched out on the unit sphere U(Us) by projection pursuit. Finally, the interpretation information is used to discover some chemical knowledge concerning the variation of the retention index with the change in chemical structures.
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External factor variable connectivity index. JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES 2003; 43:773-8. [PMID: 12767135 DOI: 10.1021/ci0340052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new variable index, external factor variable connectivity index (EFVCI), is proposed, in which the atomic attribute is divided into two parts. The innate part is denoted as outer-shell electrons and external part or perturbation by other atoms is represented as summation, multiplied by a variable x, of squared reciprocal matrix of i row (corresponds to atom A(i)). The division of atomic attribute in EFVCI is interpreted by using topological structure. In the correlation of boiling point of 149 acyclic alkanes, the optimal values will approach to a constant at -0.29 by using the zero to higher order indices of the same series. The new index, with high regression quality (R = 0.9986, s = 2.26, and F = 7088.4), is compared favorably with variable connectivity index and molecular connectivity index.
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An immunoelectron microscopic study of peptide substances in the rat neurohypophysis. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1989; 9:29-35. [PMID: 2474669 DOI: 10.1007/bf02933741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The ultrastructural localization of peptide substances, such as vasopressin (VP), substance P (SP), enkephalin (ENK) and somatostatin (SRIF), and the distribution of peptidergic nerves in rat neurohypophysis were studied by immunoelectron microscopy. The results show that VP, SP, ENK and SRIF immunoreactive products are located in large granular vesicles (110-150 nm in diameter), at the periphery of microvesicles and on the outer membrane of mitochondria. The VP-, SP-, ENK- and SRIF- containing nerve fibers are distributed at the periphery of capillaries and in the vicinity of pituicytes. VP- and ENK-positive nerve terminals form axo-axonic synapses with negative terminals. VP- and ENK-terminals are pre- or postsynaptic elements. Axo-axonic synapses formed by two SRIF- positive terminals were also found. In addition, ENK- and SP-positive terminals with pituicytes form synaptoid structures respectively. The authors have discovered VP-positive pituicytes for the first time.
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Clinical value of detecting platelet-associated IgG in patients with idiopathic thrombocytopenic purpura. ACTA ACADEMIAE MEDICINAE WUHAN = WU-HAN I HSUEH YUAN HSUEH PAO 1982; 2:170-5. [PMID: 6891958 DOI: 10.1007/bf02858452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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