分析与综合相统一方法在实践中应注意的问题

创新是知识经济时代的灵魂。而创新的实质在于对以往知识的重新建构和整合,它既表现出人的思维素质,也体现出思维方法的重要性。分析与综合相统一法是改造自然和社会的科学思维方法,如何在社会实践中正确使用、产生积极的效果,把握其关节点和多结果性是两个前提。

Effect of Crystallization Conditions on Polymorphic Diversity of Malic Acid RS-Racemate

Enantiomers （R （＋） and S（-））, RS-racemate mixture of enantiomers） of malic acid C4H605 have been （double compound） and （R ＋ S） -conglomerate （mechanical investigated by means of X-ray diffractometry and high tern- perature X-ray diffraction method. The RS-racemate was found to be able to form three polymorphic modifications, which we denominated as M1 （monoclinic, space group P21/c）, M2 （monoclinic, space group Cc）, and Tc （triclinic, space group P-l ）, the latter modification having been unknown before. Modification Tc was also described, and its X- ray diffraction characteristics, including interplanar spacings d, hkl indices, unit cell parameters, were defined. In addi- tion, X-ray diffraction characteristics for both reported earlier M1 and M2 monoclinic polymorphic modifications were measured with higher accuracy. The ability of RS-racemate to form one of the above three modifications （MI, M2, and Tc） or their mixtures containing various proportions and combinations of the components （M1 ＋ M2, M1 ＋ Tc, or M2 ＋ Tc） was found to depend on the type of crystallization medium （a melt, aqueous medium, ethanol or acetone solu- tion）, crystallization rate （from 2--3 minutes to 4 months）, and crystallization temperature. Heating S-enantiomer and M1 RS-racemate up to their respective melting points （100 ℃ and 124 ℃, correspondingly） only made them undergo thermal deformations, while heating （R ＋ S） -conglomerate in the temperature range of 96--110 ℃ resulted in its homogenization to form M2 RS-racemate, which, near the melting point （118 ℃）, namely, in the range of 112-116 ℃, was transformed into MI RS-racemate. Keywords： polvmorDhism; racemic, chiral

Similarity measure design for high dimensional data

Information analysis of high dimensional data was carried out through similarity measure application. High dimensional data were considered as the a typical structure. Additionally, overlapped and non-overlapped data were introduced, and similarity measure analysis was also illustrated and compared with conventional similarity measure. As a result, overlapped data comparison was possible to present similarity with conventional similarity measure. Non-overlapped data similarity analysis provided the clue to solve the similarity of high dimensional data. Considering high dimensional data analysis was designed with consideration of neighborhoods information. Conservative and strict solutions were proposed. Proposed similarity measure was applied to express financial fraud among multi dimensional datasets. In illustrative example, financial fraud similarity with respect to age, gender, qualification and job was presented. And with the proposed similarity measure, high dimensional personal data were calculated to evaluate how similar to the financial fraud. Calculation results show that the actual fraud has rather high similarity measure compared to the average, from minimal 0.0609 to maximal 0.1667.

Risk factors for rebleeding after angiographically negative acute gastrointestinal bleeding

AIM:To identify possible predictive factors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.METHODS: From January 2000 to July 2007, 128 patients with acute non-variceal gastrointestinal bleeding had negative f indings after initial angiography. Clinical and laboratory parameters were analyzed retrospectively.RESULTS: Among 128 patients, 62 had no recurrent gastrointestinal bleeding and 66 had recurrent gastrointestinal bleeding within 30 d. As determined by the use of multivariate analysis, an underlying malignancy, liver cirrhosis and hematemesis were significant factors related to recurrent gastrointestinal bleeding.CONCLUSION: Clinical factors including underlying malignancy, liver cirrhosis, and hematemesis are important predictors for rebleeding after angiographically negative findings in patients with acute non-variceal gastrointestinal bleeding.

Pseudopneumoperitoneum in chronic intestinal pseudo-obstruction:A case report

Chronic intestinal pseudo-obstruction(CIPO) is a rare disease due to a severe gastrointestinal motility disorder which may mimic,on both clinical and radiological grounds,mechanical obstruction.We report a case of a 26-year-old woman who presented to our institution for plain abdominal radiography for referred long-lasting constipation with recurrent episodes of abdominal pain and distension.At X-ray,performed both in the upright and supine position,an isolated air-fluid level was depicted in the left flank,together with a number of radiological signs suggestive of pneumoperitoneum.First,subphrenic radiolucency could be observed in the upright film.Second,the intestinal wall of some jejunal loops appeared to be outlined in the right flank.Third,the inferior cardiac border was clearly depicted in the upright film.The patient however had no evidence ofperitoneal signs but only hypoactive bowel movements.Unenhanced multi-detector computed tomography(MDCT) of the abdomen and pelvis was therefore performed.MDCT revealed abnormal air-driven distension of the small and large bowel,without evidence of extraluminal air.All radiological signs of pneumoperitoneum turned out to be false-positive results.The patient was submitted to pan-colonoscopy and to anorectal manometry to rule out Hirshprung's disease,and was finally discharged with a diagnosis of CIPO.

Coagulation factor Ⅶ gene polymorphisms are not associated with the occurrence or the survival of hepatocellular carcinoma:a report of 37 cases

Objective: Coagulation factor VII(FVII) triggers the extrinsic pathway of blood coagulation. In our previous study, we showed that FVII plays an important role in tumorigenesis of hepatocellular carcinoma(HCC). However, the role of FVII polymorphism in HCC is still unknown. The present study aimed to investigate the relationship between HCC carcinogenesis and single nucleotide polymorphism of FVII.Methods: Thirty-seven HCC patients and 30 healthy donors were recruited in this study. Four common FVII gene polymorphisms– a decanucleotide insertion at position –323(–323 ins10-bp), a G to T substitution at position –401(–401 G/T), a G to A substitution at position –402(–402 G/A), and a T to C substitution at position –122(–122 T/C) – were analyzed by sequencing or commercialized assays using genomic DNA isolated from blood samples. Clinicopathological parameters between control and HCC subjects were compared according to the specific genotypes.Results: The most common nucleotide variation was –402 G/A. However, no statistically significant difference was observed between healthy controls and HCC subjects for all four polymorphisms in terms of genotype distribution and allele frequencies,indicating that these polymorphisms may not affect HCC tumorigenesis. Furthermore, no association was found between–402 G/A polymorphisms and tumor stage, recurrence, and overall survival.Conclusions: Our results indicate that FVII polymorphisms may not be a key factor that clinically impact tumorigenesis and outcomes of HCC, although further investigations should be conducted to confirm our findings.