Setting Time and Strength Monitoring of Alkali-Activated Cement Mixtures by Ultrasonic Testing

Alkali-activated cement (AAC) is a promising binder that replaces ordinary Portland cement (OPC). In this study, the development of setting time and strength of AAC mixes were studied using ultrasonic testing method. The test results were compared with traditional Vicat setting time and compressive and flexural strengths. The findings showed that setting times and strengths have a strong correlation with ultrasonic velocity curve. The initial setting time corresponds well with the ultrasonic velocity curve’s dormant period, and the final setting time with the time it takes to reach the velocity curve’s maximum acceleration. Both setting times also showed a correlation with the value of the maximum acceleration. An exponential relation was found between the ultrasonic velocity and the compressive and flexural strengths. The effect of binder content, alkaline solid to binder ratio (AS/B), sodium silicate to sodium hydroxide solids ratio (SS/SH), and total water to total solid binder ratio (TW/TS) on the strength and setting time are also studied using Taguchi method of experimental design. AS/B ratio showed a significant influence on the setting time of AAC while TW/TS ratio showed only a minor effect. The ultrasonic velocities were able to capture the effect of the different parameters similar to the compressive strength. The velocity decreased mainly with the increase of TW/TS ratio and binder content, while AS/B and SS/SH ratios showed a lower influence.     

Exposure of blood from patients with sickle cell disease to air changes the morphological, oxygen-binding, and sickling properties of sickled erythrocytes

We collected venous blood samples from 7 steady-state patients with homozygous sickle cell disease under venous oxygen pressure without exposure to air (UnExp-blood) and compared the morphological, oxygen-binding, and sickling properties with those of SS cells in aliquots of the same venous blood samples that were oxygenated in room air or at a PO2 near 180 mmHg (Exp-blood). Results showed that (1) upon deoxygenation under nitrogen, UnExp-blood generated a significantly higher percentage of elongated reversibly sickled cells (RSCs) than did Exp-blood; (2) upon gradual oxygenation of completely deoxygenated sickled cells, RSCs in UnExp-blood converted to discocytes at a higher oxygen pressure than did those in Exp-blood; (3) the degree of hysteresis between the sickling/desickling curves of UnExp-blood was greater than that of Exp-blood; and (4) deoxy-Hb S in hemolysate prepared from SS cells in UnExp-blood polymerized without a delay time, while those from Exp-blood polymerized with a distinct delay time. The in vivo properties of RSCs significantly changed upon oxygenation. We also found that the various properties of blood samples collected from patients with SCD by the ordinary method were similar to those of Exp-blood, probably because such blood samples are exposed to oxygen through air in the needle, syringe, and Vacutainer. Once SS cells were oxygenated, the in vivo properties of RSCs could not be recovered by partial deoxygenation to venous oxygen pressure.     

Intravascular ultrasound-guided percutaneous transluminal coronary angioplasty with provisional spot stenting for treatment of long coronary lesions.

OBJECTIVES: The purpose of this study was to evaluate the approach of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary angioplasty (PTCA) with spot stenting (SS) for the treatment of long coronary lesions. BACKGROUND: Treating long coronary lesions with balloon angioplasty results in suboptimal short- and long-term outcomes. Full lesion coverage with traditional stenting (TS) has been associated with a high restenosis rate. METHODS: We prospectively evaluated a consecutive series of 130 long lesions (>15 mm) in 101 patients treated with IVUS-guided PTCA and SS. The results were compared with those of TS in a matched group of patients. Coronary angioplasty was performed with a balloon to vessel ratio of 1:1, according to the IVUS media-to-media diameter of the vessel at the lesion site, to achieve prespecified IVUS criteria: lumen cross-sectional area (CSA) > or =5.5 mm(2) or > or =50% of the vessel CSA at the lesion site. The stents were implanted only in the vessel segment where the criteria were not met. RESULTS: In the SS group, stents were implanted in 67 of 130 lesions, and the mean stent length was shorter than that of lesions in the matched TS group (10.4 +/- 13 mm vs. 32.4 +/- 13 mm, p < 0.005). The 30-day major adverse cardiac event (MACE) rate was similar (5%) for both groups. Angiographic restenosis was 25% with IVUS-guided SS, as compared with 39% in the TS group (p < 0.05). Follow-up MACE and target lesion revascularization rates were lower in the SS group than in the TS group (22% vs. 38% [p < 0.05] and 19% vs. 34% [p < 0.05], respectively). CONCLUSIONS: Intravascular ultrasound-guided SS for the treatment of long coronary lesions is associated with good acute outcome. Angiographic restenosis and follow-up MACE rates were significantly lower than those with TS.     

Replication of duplex DNA of phage phi X174 reconstituted with purified enzymes.

Replication of the covalently closed duplex replicative form (RF) of phage phi X174 DNA has been achieved by coupling two known enzyme systems: (i) synthesis of viral strand circles (SS) from RF, and (ii) conversion of SS to nearly complete RF (RF II). In this coupled system, activated RF (gene A . RF II complex) was a more efficient template and generated as many as 10 RF II molecules per RF input, at a rate commensurate with SS synthesis. The 11 proteins required for the two component systems were all needed in the coupled RF duplication system; no new factors were required. Single-stranded DNA binding protein was needed for RF duplication at only 4% the level needed in its stoichiometric participation in SS synthesis. In addition to RF II, more complex replicative forms appeared late in the reaction, and their possible origin is discussed.     

体外青蒿素衍生物抗卡氏肺孢子虫作用的PCR-SSCP分析

目的　研究双氢青蒿素、青蒿琥酯对卡氏肺孢子虫胸腺嘧啶合成酶基因 (TS)、二氢叶酸还原酶基因 (DHFR)的影响。方法　用不同浓度的双氢青蒿素、青蒿琥酯作用于体外培养的卡氏肺孢子虫。用药 7天后收集培养液提取卡氏肺孢子虫DNA ,分别进行PCR扩增 ,将扩增产物作DNA的单链构象多态性分析 (SSCP)。结果　卡氏肺孢子虫TS基因和DHFR基因的扩增产物分别为 40 3和 2 73bp。经青蒿素衍生物作用后TS基因、DHFR基因在溴化乙锭染色上的强度均有明显减少。继续作SSCP分析发现 ,用药组与不用药组对比DHFR基因DNA条带无明显差别 ,而用TS基因DNA条带中有一条带的位置发生改变 ,提示该基因可能出现变异。结论　SSCP分析结果提示青蒿素衍生物对卡氏肺孢子虫的DHFR基因结构无影响 ,而TS基因则可能出现部分变异。提示TS基因可能是该类药物抗卡氏肺孢子虫的机理之一     

Combined Peridynamics and Discrete Multiphysics to Study the Effects of Air Voids and Freeze-Thaw on the Mechanical Properties of Asphalt

This paper demonstrates the use of peridynamics and discrete multiphysics to assess micro crack formation and propagation in asphalt at low temperatures and under freezing conditions. Three scenarios are investigated: (a) asphalt without air voids under compressive load, (b) asphalt with air voids and (c) voids filled with freezing water. The first two are computed with Peridynamics, the third with peridynamics combined with discrete multiphysics. The results show that the presence of voids changes the way cracks propagate in the material. In asphalt without voids, cracks tend to propagate at the interface between the mastic and the aggregate. In the presence of voids, they ‘jump’ from one void to the closest void. Water expansion is modelled by coupling Peridynamics with repulsive forces in the context of Discrete Multiphysics. Freezing water expands against the voids’ internal surface, building tension in the material. A network of cracks forms in the asphalt, weakening its mechanical properties. The proposed methodology provides a computational tool for generating samples of ‘digital asphalt’ that can be tested to assess the asphalt properties under different operating conditions.     

Spleen in sickle cell anemia: Comparative studies of Nigerian and U.S. patients

Anecdotal reports have attributed persistent splenomegaly in African sickle cell anemia (SS) patients to the effects of malaria. However, no comparative studies of patients in malarial and nonmalarial regions have been conducted, and few studies of malaria antibody titers have been reported. In the present study, age- and sex-matched Nigerian and U.S. steady-state SS patients were compared. Splenomegaly was found in 22.3% of Nigerian patients (n = 310), while it was found only in 8% of U.S. patients (n = 100) from Georgia. There was significant linear correlation between spleen size and Hb levels and with serum immunoglobulins in the Nigerian group. However, serum complement levels (C3 and C4) were not affected by spleen size. In both groups, patients with splenomegaly had fewer circulating pitted red cells than their counterparts without splenomegaly. The mean ± SE of IgG-specific malaria antibody titer among the Nigerian patients without palpable spleens was 9,386 ± 2,036; 9,334 ± 2,980 in those with spleens between 1 and 5 cm, 16,201 ± 4,502 in those with spleens between 6 and 10 cm, and 22,445 ± 8,456 in those with spleens above 10 cm. Coexistent α-thalassemia did not influence the prevalence of splenomegaly among the Nigerian SS patients. This study provides additional evidence that malaria plays a significant role in the persistence of splenomegaly in African patients. © 1993 Wiley-Liss, Inc.     

How to use image analysis for islet counting

AIM: Assessment of islet mass before islet transplantation requires a reliable technique to enable exact analysis of islet volume. This study aimed to test the applicability of digital image analysis (DIA) for evaluation of samples of purified and non-purified islets. METHODS: Pancreatic islets were isolated from 10 Lewis rats. Samples of purified (n = 10) and non-purified islets (n = 30) were counted conventionally and by using a computerized method. The equipment for the computerized counting consisted of a digital camera installed on a stereomicroscope and connected to a personal computer. Images of 2272x1704 pixels were processed using a previously described non-commercial program originally developed for this purpose. Islets were converted to equivalents using globe and ellipsoid models. The insulin content of purified islets was assessed using radioimmunoassay and was correlated to the absolute and standardized islet number. RESULTS: Mean absolute numbers of purified islets ± SD were 908 ± 130 and 1049 ± 230 (manually and DIA respectively). Mean insulin content ± SD obtained from purified islets was 161 ± 45 mU. The mean equivalents of purified islets (1589 ± 555 for globe and 1219 ± 452 for ellipsoid) significantly correlated with insulin content. However, this correlation was not significant when absolute islet numbers were used, counted using either method. There was no significant difference in absolute non-purified islet numbers assessed by manual and computerized methods (average ± SD in 50 µl samples; 12.6 ± 4.1 and 13.3 ± 5.3 respectively; p = 0.22). The manual method showed a significantly higher yield of islet equivalents (IE; p < 0.001 for both globe and ellipsoid). CONCLUSION: The computer-based system for islet counting correlated better to insulin content than conventional islet estimation and prevented overestimation. Reproducibility and ease of assessment make it potentially applicable to clinical islet transplantation.     

Relationship of heart rate turbulence, heart rate variability and the number of ventricular premature beats in patients with mitral valve prolapse and non-significant regurgitation

Cardiac arrhythmia is frequently detected in patients with mitral valve prolapse (MVP) and improper autonomic tone is considered the etiology. Heart rate turbulence (HRT) and heart rate variability (HRV) are methods assessed for autonomic dysfunction. To evaluate whether the number of ventricular premature contractions (VPCs) is influenced by HRT or HRV in patients with MVP. Holter monitoring for the number of VPCs and correlation analysis with HRT and HRV was performed. There were 31% and 3% with abnormal turbulence onset (TO) and turbulence slope (TS) values in totally 68 patients. No significant correlation is found between the number of VPCs and HRT, HRV parameters. In analysis the relationship between HRT and HRV parameters, TS has higher correlation with HRV than TO values, particular in time-domain.     

Assessment of atrial septal defect size with 3D-transesophageal echocardiography: comparison with balloon method

BACKGROUND: Transcatheter closure of atrial septal defect (ASD) is an alternative approach to surgery in selected patients. Balloon stretched diameter (BSD) is considered as the standard way of measuring ASD size. Three-dimensional transesophageal echocardiography (3D-TEE) provides views of the ASD allowing its measurement and identifying its spatial relation with neighboring structures. Our aim was to compare the BSD and 3D-TEE methods to measure the ASD size before transcatheter closure. METHODS AND RESULTS: Seventy-six consecutive patients were enrolled for ASD device closure. Three-dimensional transesophageal echocardiography and balloon sizing were adequately performed in 70 patients before the defect closure. The mean maximal diameter measured by 3D-TEE was 20 +/- 15 mm (range 10-28) while the mean BSD was 22 +/- 4.8 mm (range 9-31). When comparing the 3D-TEE and transcatheter measurements, there was a good correlation between the two methods (y = 3.15 + 0.77x; r = 0.8). The defect as viewed by 3D-TEE was unique in 54 patients and multiple in 16 patients. In patients with a single defect, the correlation between the two methods was high (y = 1.74 + 0.84x; r = 0.85) while patients with multiple ASDs, the correlation was poor (y = 12.4 + 0.4x; r = 0.45). Transcatheter closure was performed successfully in 86%. The mean size of the Amplatzer device was 23 +/- 4.8 mm (range 4-32). The reference to choose the size of the device was the BSD in single defects and the 3D-TEE maximal diameter in multiple defects. CONCLUSION: Three-dimensional transesophageal echocardiography and transcatheter methods are two complementary techniques for the success of transcatheter ASDs closure.     

Young elite athletes of different sport disciplines present with an increase in pulsatile secretion of growth hormone compared with non-elite athletes and sedentary subjects

Acute exercise is a well-known stimulus for GH secretion but the effect of chronic training on GH secretion still remains equivocal. The aim of our study was to analyse spontaneous pulsatile GH secretion (during a period of 2 hours in the morning) in a group of young elite athletes (EA) compared with non-elite athletes (NEA), and sedentary subjects (SS). Mean and peak GH levels proved significantly higher in EA than in NEA and SS (p=0.0004 and p<0.0001, respectively). The same differences in mean and peak GH levels were also demonstrated in males and females when considered separately (males: p=0.0062 and p=0.0025; females: p=0.0056 and p=0.0032). In addition, GH levels (mean and peak) were higher in females than in males in SS while no differences were demonstrated between the 2 sexes in the EA and NEA groups. IGF-I levels were within the normal range for age in all the subjects with no difference between the 3 groups. Body mass index (BMI) exhibited no difference between groups, while EA showed higher lean mass (p=0.0063) and lower fat mass (p=0.0139) than NEA and SS measured by dual-energy x-ray absorptiometry. A strong positive correlation between GH levels (mean and peak) and hours of training a week was demonstrated (p=0.0101; r2=0.1184; p=0.0022; r2=0.1640, respectively). In conclusion, GH levels were higher in EA than NEA and SS without any modification of IGF-I levels; a strong positive correlation was present between GH levels and intensity of training. An increase in the knowledge of the effect of chronic training on GH secretion could improve the training programme to elicit the greatest exercise- induced GH response.     

Expression of metalloproteinase-2 (gelatinase A) in labial salivary glands of patients with Sj?gren's syndrome with HTLV-I infection.

OBJECTIVE: To determine whether gelatinase A (MMP-2) plays a significant role in the pathogenesis of Sj?gren's syndrome (SS) with or without HTLV-I infection. METHODS: We examined 24 patients with SS (14 HTLV-I-seropositive and 8 HTLV-I-seronegative). Labial salivary gland tissue samples were analysed immunohistochemically using anti-MMP-2 monoclonal antibodies. RESULTS: In normal salivary glands, MMP-2 expression was not detected. All biopsy samples of 8 SS patients with HTLV-I-associated myelopathy (HAM) and 3 of 6 HTLV-I-seropositive SS patients without manifestation of HAM stained positively for MMP-2. However, the other samples were negative for MMP-2. CONCLUSION: Our study showed the MMP-2 expression in labial salivary glands of HTLV-I seropositive SS patients, especially in all SS patients with HAM. The presence of MMP-2 in the salivary glands of these patients suggests that it may play a role in cellular infiltration and destruction in salivary glands of SS.     

消化性溃疡,胃癌患者胃窦粘膜中胃肠激素含量变化及其意义

研究了胃十二指肠疾病患者胃窦粘膜胃泌素（Ｇａｓ）、生长抑素（ＳＳ）、Ｐ－物质（ＳＰ）的含量变化及其意义。结果表明：胃窦粘膜ＳＳ含量在胃溃疡组低于其余各组（Ｐ均〈０．０５），而在胃癌时则显著增高（Ｐ〈０．００１）；ＳＰ浓度在十二指肠溃疡组显著低于其余各组（Ｐ均〈０．０５）；胃癌患者Ｇａｓ水平显著高于对照组（Ｐ〈０．０５）；ＳＳ与ＳＰ在十二指肠溃时呈明显负相关。提示：胃粘膜中Ｇａｓ、ＳＳ、ＳＰ的含量变     

Quantitative evaluation of regional blood flow in pulmonary sarcoidosis with bull's eye analysis]

Lung perfusion scintigraphy was performed in 23 patients with pulmonary sarcoidosis and in 11 normal volunteers. Bull's eye analysis was used to analyze regional pulmonary blood flow quantitatively. First, whole lung perfusion images were divided into three regions by three concentric circles. Then radial axes were projected from the center to define 36 x 10 degrees sectors. The counts for each sector were calculated and a Bull's eye image was displayed. The counts were compared with the lower limit of normal (mean - 2SD), and as the indices of reduction in perfusion, extent score (ES) and severity score (SS) were calculated. ES and SS showed significant reduction in perfusion 16 patients (70%) with sarcoidosis. In stage II sarcoidosis, both ES and SS were significantly higher than in stage I sarcoidosis (p less than 0.05). In comparison with the findings of transbronchial lung biopsy, both ES and SS had correlations with the degree of alveolitis and ES had a correlation with the degree of angiitis. Both ES and SS have no correlation with 67Ga scintigraphy findings. In comparison with clinical data, ES had a positive correlation with serum angiotensin-converting enzyme activity (p less than 0.05), and SS had a significant positive correlation with bronchoalveolar lavage fluid.CD+/CD8+ ratio (p less than 0.05). The Bull's eye analysis was considered useful for the quantitative evaluation of regional pulmonary blood flow in pulmonary sarcoidosis, and it was suggested that the mechanism of reduction in perfusion might be resulted mainly in its alveolitis and angiitis. Ventilation abnormality, which may happen prior to reduction in perfusion, may be an important factor of reduction in perfusion.     

Quantitative liver functions in Turner syndrome with and without hormone replacement therapy

BACKGROUND: Studies have documented elevated levels of liver enzymes in many females with Turner syndrome (TS). Histology has shown a range of changes. Treatment with female hormone replacement therapy (HRT) reduces liver enzymes. AIM: To study quantitative liver functions in TS in detail with and without HRT. DESIGN: Randomized crossover study with active treatment (HRT in TS and P-pill in controls) or no treatment. SUBJECTS: Women with TS (n = 8, age 29.7 +/- 5.6 (mean +/- s.d.) years), verified by karyotype, and age-matched controls (C; n = 8, age 27.3 +/- 4.9 years). METHODS: We determined liver enzymes in blood, used the galactose elimination capacity to assess hepatocyte cytosol activity, plasma clearance of indocyanine green to assess excretory function, antipyrine clearance to estimate microsomal activity, and the functional hepatic nitrogen clearance (FHNC) to assess mitochondrial-cytosolic metabolic capacity for conversion of amino-nitrogen. RESULTS: Liver enzymes were elevated in untreated TS and reduced by HRT. The hepatic capacities for conversion of galactose, indocyanine green, and antipyrine were normal and did not change by HRT. The FHNC was marginally reduced (untreated TS vs C: 19.4 +/- 5.4 vs 25.2 +/- 7.3 L/h, P = 0.1). FHNC changed slightly with HRT in TS (19.4 +/- 5.4 vs 24.4 +/- 10.2 L/h, P = 0.2). CONCLUSIONS: The elevations of liver enzymes in untreated TS are readily suppressed by HRT. Quantitative liver functions in TS are comparable to controls and are not affected by HRT.     

Electrocardiographic detection of left atrial enlargement. Correlation of P wave with left atrial dimension by echocardiography.

The validity of various electrocardiographic P wave measurements was tested in 48 patients by comparing them to left atrial dimensions determined by echocardiography (echo), a proved method of left atrial size estimation. Of all the measurements considered, only the width of the P wave (PW), the P terminal force in lead V1 (PV1), and the PW/PR segment ratio (PW/PR) showed statistically significant correlations with left atrial size measurements by echo, with r values of 0-746, 0-491, and 0-479, respectively. The results indicated that P widths in excess of 105 ms were present in all the patients who had left atria equal to or greater than 3-8 cm by echo and in 11 per cent of patients without atrial enlargement (false positives), and that when measurements were less than 105 ms left atrial enlargement was unlikely.     

Electrocardiographic detection of left atrial enlargement. Correlation of P wave with left atrial dimension by echocardiography.

The validity of various electrocardiographic P wave measurements was tested in 48 patients by comparing them to left atrial dimensions determined by echocardiography (echo), a proved method of left atrial size estimation. Of all the measurements considered, only the width of the P wave (PW), the P terminal force in lead V1 (PV1), and the PW/PR segment ratio (PW/PR) showed statistically significant correlations with left atrial size measurements by echo, with r values of 0-746, 0-491, and 0-479, respectively. The results indicated that P widths in excess of 105 ms were present in all the patients who had left atria equal to or greater than 3-8 cm by echo and in 11 per cent of patients without atrial enlargement (false positives), and that when measurements were less than 105 ms left atrial enlargement was unlikely.     

Intratumoral heterogeneous expression of thymidylate synthase in gastric cancer

BACKGROUND/AIMS: Thymidylate synthase (TS) is reported to be a predictive factor of survival in gastric cancer patients. Its heterogeneous expression has been observed in various cancerous lesions but has not been assessed intratumorally. The aim of this study was to determine the most pertinent site for investigating intratumoral TS expression for the prediction of survival. METHODOLOGY: TS staining grade was evaluated at the center (CT), the horizontal edge (HT) and the vertical edge (VT) of the tumor, and TS protein level was determined by ELISA at CT and HT. Proliferating cell nuclear antigen (PCNA) was examined for proliferation markers in all tumor samples. RESULTS: TS expression at HT and VT was significantly higher than at CT. A positive correlation was observed between TS protein level and PCNA-Labeling Index at HT, but not at CT. The survival rate of the high TS group was poor compared with the low TS group at HT and VT, but not at CT. CONCLUSIONS: The horizontal edge of the tumor (HT) is the most pertinent site for the evaluation of TS expression in gastric cancer; it could prove especially useful in the presurgical estimation of prognosis through biopsy samples.     

A study of the usefulness of pancreatic juice cytology obtained via an endoscopic nasal pancreatic drainage (ENPD) tube

We studied the usefulness of pancreatic juice cytology obtained via an indwelling endoscopic nasal pancreatic drainage (ENPD) tube. In general, cytology was performed three times. The sensitivity was 0.35 on the first time and 0.59 after three times (p<0.01). The sensitivity in relation to tumor size of pancreatic cancer was 0.77 for Tis (3 cases) and TS1 (10 cases), 0.76 for TS2 (29 cases), 0.56 for TS3 (9 cases) and 0 for TS4 (4 cases). A significant difference of p=0.01 was recognized among the 4 groups, and the sensitivity for small tumors was higher than that for large tumors. The pancreatic juice can be obtained repeatedly via the ENPD tube and that contributes to improving the diagnostic accuracy. It is useful as a definitive diagnosis method in early stage pancreatic cancer because it is easier to detect positive results in smaller tumor, furthermore, it is possible to diagnose carcinoma in situ.