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Three new metal chalcogenides have been identified in Mn

Experimental studies of polymer melt flow in the filling and post-filling stages of the injection molding process were performed using the sequential injection of transparent and colored polystyrene resin. Effects of fountain flow in the filling stage, geometrical factors caused by edges and corners, as well as flow through contractions and expansions, were identified. Significant polymer melt flow which increases with increased packing pressure was observed in the post-filling process. The melt flow is more concentrated around the gate area than away from the gate. It was also found that the polymer melt flows across the gap center, resulting in partial annihilation of the weld line. Simulations based on the control-volume/finite-element method employed within each gapwise layer combined with the dual-filling-parameter technique were developed to trace the advancements in melt fronts for both skin and core materials. Numerical simulations show reasonable consistency with experimental results in both skin and core material distribution. If the edge effect is taken into account using a shape factor as a geometrical correction, the simulation accuracy is further improved.

Characteristics of gas penetration and polymer melt flow in gas-assisted injection molded spiral tubes was investigated by simulations and experiments. Distribution of the skin melt thickness along the gas flow direction was measured, and gas penetration in the primary and secondary stages was identified. An algorithm based on the control-volume/tiniteelement method combined with a particle-tracing scheme using a dual-filling-parameter technique is utilized to predict the advancements of both melt front and gas from during the molding process. The simulated distribution of gas penetration shows reasonably good coincidence with experimental observations. © 1995 John Wiley & Sons, Inc.

Two algorithms are developed to predict the polymer melt front advancement in the thin plate with ribs of semicircular cross section. In the first method, rod-like elements of equivalent hydraulic diameter representing a semicircular rib are superimposed on the triangular shell element mesh used for the thin section. In the second approach, rectangular elements having the same width as the diameter of the semicircular rib and representing mixed one- and two-dimensional flow characteristics are used and interlinked with triangular elements. In both algorithms, control volume /finite element formulation is applied to trace the melt front advancement. Both simulations result in similar predictions and also show reasonably good consistency with experimental observation.

Although phytobezoars are a rare cause of gastrointestinal obstruction, they are most commonly found in patients with previous gastric surgery. It is well known that predisposing factors of phytobezoar formation are ingestion of fruits containing soluble tannin, presence of dilute hydrochloric acid in the stomach, and gastric stasis or delayed emptying. We investigated whether intake of acid-suppressing drugs that neutralize gastric acidity or inhibit gastric acid secretion to constitute a hypo-acidic condition, increases the risk of phytobezoar formation.Between September 1992 and October 2008, 32 patients (24 male and 8 female) with gastrointestinal phytobezoars were diagnosed either surgically or endoscopically at the Tri-Service General Hospital, Taipei, Republic of China. The data were collected from hospital records and analyzed retrospectively.Eighteen (56.25%) of all patients had previous gastric surgery and 6 (42.9%) of the 14 patients who had not undergone surgery had diabetes mellitus. The majority of admissions were during winter and spring (between October and March) (P0.01) and none of the patients had taken acid-suppressing drugs during the 6 months before detection of gastrointestinal phytobezoars.In our study, intake of acid-suppressing drugs did not increase the risk of phytobezoar formation in patients with normal gastric motility. Moreover, we believe that the major factor in phytobezoar formation is gastric stasis or delayed emptying, which sufficiently prolongs the retention period of materials in the stomach, while dilute hydrochloric acid is a minor factor.

Antigen-specific cancer immunotherapy and antiangiogenesis have emerged as two attractive strategies for cancer treatment. An innovative approach that combines both mechanisms will likely generate the most potent antitumor effect. We tested this approach using calreticulin (CRT), which has demonstrated the ability to enhance MHC class I presentation and exhibit an antiangiogenic effect. We explored the linkage of CRT to a model tumor antigen, human papilloma virus type-16 (HPV-16) E7, for the development of a DNA vaccine. We found that C57BL/6 mice vaccinated intradermally with CRT/E7 DNA exhibited a dramatic increase in E7-specific CD8(+) T cell precursors and an impressive antitumor effect against E7-expressing tumors compared with mice vaccinated with wild-type E7 DNA or CRT DNA. Vaccination of CD4/CD8 double-depleted C57BL/6 mice and immunocompromised (BALB/c nu/nu) mice with CRT/E7 DNA or CRT DNA generated significant reduction of lung tumor nodules compared with wild-type E7 DNA, suggesting that antiangiogenesis may have contributed to the antitumor effect. Examination of microvessel density in lung tumor nodules and an in vivo angiogenesis assay further confirmed the antiangiogenic effect generated by CRT/E7 and CRT. Thus, cancer therapy using CRT linked to a tumor antigen holds promise for treating tumors by combining antigen-specific immunotherapy and antiangiogenesis.

Certain domains of bacterial toxins have been shown to facilitate translocation from extracellular and vesicular compartments into the cytoplasm. This feature represents an opportunity to enhance class I presentation of exogenous antigen to CD8(+) T cells. We investigated this notion by creating a novel fusion of the translocation domain (domain II) of Pseudomonas aeruginosa exotoxin A (ETA(dII)) with a model tumor antigen, human papillomavirus type 16 E7, in the context of a DNA vaccine. Our in vitro studies indicated that cells transfected with ETA(dII)/E7 DNA or dendritic cells pulsed with lysates containing ETA(dII)/E7 protein exhibited enhanced MHC class I presentation of E7 antigen. Vaccination of mice with ETA(dII)/E7 DNA generated a dramatic increase in the number of E7-specific CD8(+) T cell precursors ( approximately 30-fold compared with wild-type E7 DNA) and converted a less effective DNA vaccine into one with significant potency against human papillomavirus type 16 E7-expressing murine tumors via a CD8-dependent pathway. These results indicate that fusion of the translocation domain of a bacterial toxin to an antigen may greatly enhance vaccine potency.

Hypotonicity activates volume-sensitive Cl- currents, which are implicated in the regulatory volume decrease (RVD) responses and transport of taurine in human cervical cancer HT-3 cells. In this study, the role of cytoskeleton in the regulation of volume-sensitive Cl- channels and RVD responses in HT-3 cells was studied. Cells were incubated with various compounds, which depolymerized or polymerized cytoskeletal elements, i.e. actin filaments and microtubules. The hypotonicity-induced changes in Cl- conductance and in cell volume were measured by whole-cell voltage clamping and cell size monitoring, respectively. Our results show that in HT-3 cells hypotonicity activated an outward rectified Cl- current that was abrogated by Cl- channel blockers. Cytochalasin B, an actin-depolymerizing compound, induced a substantial increase in Cl- conductance under isotonic condition and potentiated the expression of Cl- currents in hypotonic stress. Phorbol 12-myristate 13-acetate (PMA) significantly inhibited the cytochalasin B-induced activation of Cl- conductance under isotonic condition. On the other hand, treatment with cytochalasin B significantly prolonged the RVD responses. Phalloidin, a stabilizer of actin polymerization, did not change the basal currents under isotonic condition, but completely abolished the increase in whole-cell Cl- conductance elicited by hypotonicity and retarded the cell volume recovery. Colchicine, a microtubule-assembly inhibitor, had no effect on either basal Cl- conductance or volume-sensitive Cl- current and was unable to inhibit the RVD responses. Taxol, a microtubule-stabilizing compound, did not alter the basal Cl- conductance, but inhibited the activation of volume-sensitive Cl- channels as well as the process of RVD in a dose-dependent manner. These data support the notion that functional integrity of actin filaments and microtubules plays critical roles in maintaining the RVD responses and activation of Cl- channels in human cervical cancer HT-3 cells.

Heart volume may provide important information on the status of fetal hemodynamics. However, traditionally fetal heart volume has been assessed with the erroneous assumption that the fetal heart is spherical or elliptical. With the advent of three-dimensional ultrasound, accurate assessment of organ volume has become feasible. The objectives of this study were to compare the reproducibility of two-dimensional ultrasound and three-dimensional ultrasound in the assessment of heart volume, and to test whether heart volume assessed by the traditional method of two-dimensional ultrasound equates to that assessed by three-dimensional ultrasound. If it proved to be significantly different, we aimed to find a new constant which, if incorporated into the traditional formula used to determine heart volume, would enable us to achieve more accurate volumes with two-dimensional ultrasound. In total, 50 normal singleton fetuses ranging from 20 to 30 weeks' gestation were included in the study. Both the traditional two-dimensional and the new three-dimensional volume measurements were compared. The results showed that three-dimensional ultrasound has a better reproducibility than two-dimensional ultrasound in heart volume assessment and that heart volume assessed by the traditional formula of two-dimensional ultrasound is significantly larger than that measured by three-dimensional ultrasound (p0.001). We therefore propose that, if the traditional two-dimensional equation is to be used, the constant for heart volume could be modified to 0.4563 (SE = 0.0153, n = 50) to achieve more accurate results. With this new constant, the heart volume derived by two-dimensional ultrasound was not found to differ from that measured by three-dimensional ultrasound. From our series, we conclude that three-dimensional ultrasound is theoretically the best method for the assessment of heart volume. However, because of the limitations of three-dimensional ultrasound (i.e. it is not routinely available, it is more expensive and more time-consuming) two-dimensional ultrasound in practical terms should be the method of choice. Although we were able to improve the accuracy of the heart volume measurements using a new constant in the traditional two-dimensional formula, the new constant will not improve variability, which can only be reduced by three-dimensional ultrasound.

A 22-year-old woman was referred to our hospital because of severe anemia in the 20th week of gestation. Acute myelogenous leukemia was diagnosed and she was treated with multiple-agent chemotherapy in the second and third trimesters. Although the patient tolerated the intensive treatment, an intermittent sinusoidal fetal heart rate pattern was detected during chemotherapy. Complete remission was achieved at the 35th week of gestation. An underweight baby boy, suffering from pancytopenia, was delivered by cesarean section at 36 weeks' gestation. The baby recovered well and had adequate growth. No abnormalities where found at examination two months after birth. The fetal sinusoidal heart rate pattern may have been induced by severe anemia due to myelosuppression caused by the transplacental receipt of chemotherapeutic agents.

The development and short-term clinical tests of a new type of IUD made of silicone rubber are reported. The structure of the IUD is appropriate and the excellency of in vivo stability and aging-resistant property of silicone rubber make it contraceptively effective. All this lowers the side effects (especially menorrhagia, soreness, and other uncomfortable feelings; and makes it suitable for longterm use. The materials used to produce this flower are domestically available. The technology and equipment involved are simple, and the production can easily be popularized. (author's modified)