Combined fresh and frozen embryo transfer resulting in a twin delivery

We report the delivery of non-identical twins resulting from the combined transfer of one fresh and one frozen embryo to a 31 year old patient. To our knowledge, this is the first reported case where both a fresh and a frozen embryo implanted in the same cycle led to non-identical twins. We conclude that supernumerary embryos after in-vitro fertilization should be frozen and used in subsequent cycles, with implantation potentials as high as fresh embryos. The possibility of mixing fresh and frozen embryos, though rarely needed, should be considered, particularly when there is only one fresh embryo available for transfer.     

Physical effects of immissions

In the presence of a normal (1.25 to 1.80 mM) calcium concentration, addition of fresh bovine calf serum or completely changing the medium induces proliferatively quiescent BALB/c 3T3 mouse cells in dense cultures to start a growth division cycle and initiate DNA synthesis about 12 hr later. Fresh, low-calcium (0.02 mM physiologically available) medium also causes cells to start a growth-division cycle. Howver, the development of such stimulated, calcium-deprived cells tops just before the expected time of initiation of DNA synthesis, which can then be rapidly induced by restoration of the normal calcium concentration. Simply raising the calcium concentration to nonphysiologically high levels (without otherwise altering the medium) can mimic the action of fresh serum or fresh whole medium by inducing some of the cells in proliferatively quiescent confluent concluent cultures to start a growth-division cycle and initiate DNA synthesis 22 hr later.     

Expression of the biochemical defect of methionine dependence in fresh patient tumors in primary histoculture

Methionine dependence is a metabolic defect that occurs in many human tumor cell lines but not normal in unestablished cell strains. Methionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/G2 phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (MET-HCY+ medium). However, it is not known whether methionine dependence occurs in fresh patient tumors as it does in cell lines. In order to determine whether methionine dependence occurs in fresh patient tumors as well as whether methionine dependence occurs in fresh patient tumors as well as in cell lines we took advantage of the technique of sponge-gel-supported histoculture to grow tumors directly from surgery. We then measured nuclear DNA content by image analysis to determine the cell cycle position in MET-HCY+ compared to MET+HCY- medium in 21 human patient tumors. Human tumor cell lines found to be methionine dependent by cell count were used as positive controls and were found to have marked reduction of cells in G1 compared to total cells in the cell cycle in MET-HCY+ medium with respect to the G1: total cell ratio in MET+HCY- medium. Therefore late cell cycle arrest was used as a marker of methionine dependence for histocultured patient tumors. We found that 5 human tumors of 21, including tumors of the colon, breast, ovary, prostate, and a melanoma, were methionine dependent based on cell cycle analysis. These data on fresh human tumors indicate that methionine dependence may frequently occur in the cancer patient population. Implications for potential therapy based on methionine dependence are discussed.     

Beyond ‘Six Sigma’

If your firm has reached its optimum production cycle but you need work done better and faster. What do you do? You might try a fresh perspective. Most approaches to increasing productivity, including six sigma, aim at improving current processes, concentrating on reducing an operation's average cycle time and eliminating any defects, errors, or scrap in the process. Eventually, however, a process reaches a point where it can no longer be improved. This article shows how to look beyond your traditional processes to find better, more productive ones by using experts from a variety of fields outside your own and developing these ideas into something that give you even better performance.     

The ability of thiram to inhibit eukaryotic topoisomerase II and to damage DNA

At the end of a hybridoma batch culture, the cells are usually discarded after separation from the culture broth. If, however, they are aseptically recycled into the reactor, the production process can be resumed simply by the addition of fresh medium. This cycle can then be repeated several times consecutively. In a test case, with a mouse hybridoma, we found antibody yields for each cycle in the same range as for a standard batch. In a 15 1 stirred tank reactor we could, within 6 days, produce 2.8 g of monoclonal antibody (MAb). This type of reactor operation allowed a doubling in the reactor volumetric productivity (mg/l/day).     

煤气余热开发利用技术探讨

从发生炉出来的高温热煤气,需要进入双竖管、洗涤塔循环水喷淋,出炉热煤气几乎将70%以上的显热传给竖管循环水,大量的煤气显热被浪费。为节约能源,本文探讨安装一台废热锅炉进行煤气热交换,产生可以利用的新蒸汽和软化热水的可性行。     

Immunological status of septic and trauma patients. II. Proliferative response and production of interleukin 6 and tumor necrosis factor alpha by peripheral blood mononuclear cells from septic survivor, nonsurvivor and trauma patients: a correlation with the survival rate

OBJECTIVE: The reasons for conflicting prognostic results as to DNA ploidy and cell cycle variables (DNA index, percent S (%S) phase) may be found mainly at different levels of the flow cytometric methodology used. The present study concentrated on how many nuclei have to be measured with flow cytometry for reliable DNA histogram interpretation. STUDY DESIGN: Twenty-three samples of fresh frozen and 22 samples of paraffin-embedded material from different sites were used. For each sample, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 (x1,000) events were cumulatively measured. The resulting DNA histograms were analyzed with the MultiCycle computer program using a highly reproducible interpretation protocol. RESULTS: No disagreements about DNA ploidy classification were found in samples with 10,000 or more events for the fresh frozen and 40,000 or more events for the paraffin-embedded material. Excluding DNA ploidy disagreements, the DNA index was stable in all cases. To obtain a %S-phase cell measurement within 20% of the reference value, at least 20,000 and 40,000 events were needed for, respectively, DNA diploid and DNA nondiploid cases for the fresh frozen material and, respectively, 40,000 and 50,000 events for the paraffin-embedded material. CONCLUSION: For reliable combined determination of DNA ploidy, DNA index and %S-phase cells, at least 40,000 and 50,000 events are necessary for fresh frozen and paraffin-embedded material, respectively.     

P53 mutations in tumours induced by intraperitoneal injection of crocidolite asbestos and benzo[a]pyrene in rats

Mutation analysis of the tumour suppressor gene p53 in tumours induced in the peritoneal cavity of rats revealed differences in the mutational pattern with regard to the carcinogenic substances applied. In tumours induced by benzo[a]pyrene a considerable amount of p53 mutations resulting in an altered protein structure could be detected. For the development of these tumours an escape from the p53 mediated cell cycle control can be assumed. However, in tumours of the same tumour type induced by crocidolite asbestos no mutations could be observed. Since there were even no spontaneous p53 mutations detectable in this tumour group, it is obvious that in these tumours the escape from cell cycle control does not take place via inactivation of p53. Therefore, it is concluded that the molecular mechanisms of carcinogenesis and tumour development in this tumour type depend on the type of carcinogen applied.     

Infiltration Considerations for Ground-Water Recharge with Waste Effluent

Water reuse and ground-water recharge can be used to meet the growing demands for water, particularly in arid regions. Ground-water recharge using fresh water or treated wastewater is most often accomplished by infiltration from surface basins. The water percolates through the unsaturated soil region to an underlying aquifer for storage and future use. In the case of wastewater, additional treatment occurs as the effluent flows through the soil. The system hydraulics of recharge basins have been examined through a combination of field and laboratory investigations. These studies indicate that infiltration rates and soil aquifer treatment of wastewater are influenced by soil type and soil profile characteristics, surface clogging material, pond depth, and wetting∕drying cycle times. The surface-clogging layer was found to be susceptible to consolidation and to associated reduction in hydraulic conductivity under seepage forces.     

Effect of sucrose acetate isobutyrate (SAIB) ingestion on the hepatobiliary function of normal human male and female volunteers

Monitoring of oxygen uptake during general anesthesia would have several benefits, but unfortunately, this is usually not available in the clinical routine situation. The herein proposed formula to calculate oxygen uptake (.VO2) necessitates only the accurate measurement of FIO2 as well as fresh gas flow and composition. Additionally, this method is not affected by the presence of anesthetic gases. The calculation uses the difference in oxygen content between the delivered fresh gas and the resulting FIO2 in the anesthesia circle system. This gap originates from oxygen uptake (that is mainly caused by metabolic oxygen consumption) and is more pronounced if low fresh gas flows are administered. In order to obtain representative results, calculation of .VO2 should be performed only after achievement of respiratory steady state conditions. Due to its simplicity and wide availability, it has the potential to become a valuable extension in anesthesia monitoring during the performance of routine general anesthesia.     

Modification of CaO by Organic Alumina Precursor for Enhancing Cyclic Capture of CO2 Greenhouse Gas

The modification of CaO sorbent with organic alumina precursor to enhance the sorption capacity during cyclic capture is demonstrated in this study. The results indicate that during the 10?min sorption time for each cycle, the CO2 sorption capacity of original CaO sorbent is significantly decreased from 0.27 to 0.19 and 0.12?g CO2/g sorbent after 5 and 60?cycles, respectively. On the other hand, the organic alumina modified CaO has a fresh capacity of 0.22?g CO2/g sorbent, it increases to 0.24?g CO2/g sorbent after 5?cycles, and then decreases to around 0.15?g CO2/g sorbent after 60?cycles. When increasing the sorption time to 60?min at the 66th cycle, the sorption capacity of original CaO is 0.2, whereas it is 0.26?g CO2/g sorbent for organic alumina modified CaO. The results demonstrate that by adding only 5% by weight of Ca12Al14O33 species into the CaO sorbent, the CO2 sorption capacity can be enhanced up to ～ 27% by weight.     

Radiation induced G1-block and p53 status in six human cell lines

Considerable attention has recently been focused on the fact that the tumor suppressor protein p53 is involved in the cellular response to radiation. In its wild-type form the protein appears to control a cell cycle checkpoint, preventing entry into S-phase following DNA damage. A number of authors observed a radiation induced G1-block in cells expressing wild-type p53, but not in p53 mutant cells. We obtained similar results with four human tumour cell lines as well as two strains of human fibroblasts, whose p53 status was ascertained at the protein as well as DNA levels. In addition to cell cycle delays in exponentially growing cell cultures, we have studied the possible role of the p53 in the transition from quiescence to active proliferation. Cells were irradiated after 6 days of serum-starvation and labelled with BrdU at different times after addition of fresh medium. Entry into S-phase was found to be delayed by several hours in the p53 wild-type cells, but no such effect was observed in the p53 mutants. Where a delay occurred, it was roughly proportional to the X-ray dose. Although it remains to be clarified, whether the cells were delayed only in G1 or also in G0, it is interesting to note that entry into S-phase can be delayed by irradiation in a quiescent state immediately before serum-stimulation, provided the cells are wild-type with respect to p53. Certain differences in the cell cycle response of transformed and untransformed cells were noted.     

放电温度与Li_2O_2充电极化特性关系研究

充电极化过大是制约锂空气电池应用的关键问题之一,这主要源于其放电产物Li2O2低的体相电荷传输能力。本文基于缩短体相电荷传输路径的目的,首次采用控制放电温度的技术降低Li2O2颗粒尺度,研究不同Li2O2的颗粒尺度的充电特性。研究表明,放电温度可以调控Li2O2颗粒特性,高温放电产生的Li2O2倾向在更多的碳基体上形核,颗粒更为细小,可进一步降低充电的电化学反应极化。本研究为降低锂空气电池充电极化提供了一种全新的思路。     

Hydraulic Conductivity of MSW in Landfills

This paper presents a laboratory investigation of hydraulic conductivity of municipal solid waste (MSW) in landfills and provides a comparative assessment of measured hydraulic conductivity values with those reported in the literature based on laboratory and field studies. A series of laboratory tests was conducted using shredded fresh and landfilled MSW from the Orchard Hills landfill (Illinois, United States) using two different small-scale and large-scale rigid-wall permeameters and a small-scale triaxial permeameter. Fresh waste was collected from the working phase, while the landfilled waste was exhumed from a borehole in a landfill cell subjected to leachate recirculation for approximately 1.5 years. The hydraulic conductivity tests conducted on fresh MSW using small-scale rigid-wall permeameter resulted in a range of hydraulic conductivity 2.8×10?3–11.8×10?3?cm/s with dry unit weight varied in a narrow range between 3.9–5.1?kN/m3. The landfilled MSW tested using the same permeameter produced results between 0.6×10?3–3.0×10?3?cm/s for 4.5–5.5?kN/m3 dry unit weights. The hydraulic conductivity obtained from large-scale rigid-wall permeameter tests decreased with the increase in normal stress for both fresh and landfilled waste. The hydraulic conductivity for fresh MSW ranged from 0.2 cm/s for 4.1?kN/m3 dry unit weight (under zero vertical stress) and then decreased to 4.9×10?5?cm/s for 13.3?kN/m3 dry unit weight (under the maximum applied normal stress of 276 kPa). The hydraulic conductivity of the landfilled MSW decreased from 0.2 cm/s to 7.8×10?5?cm/s when the dry unit weight increased from 3.2 to 9.6?kN/m3. The results clearly demonstrated that the hydraulic conductivity of MSW can be significantly influenced by vertical stress and it is mainly attributed to the increase in density leading to low void ratio. In small-scale triaxial permeameter, when the confining pressure was increased from 69 to 276 kPa the hydraulic conductivity decreased from approximately 10?4?to?10?6?cm/s, which is much lower than those determined from rigid-wall permeameter tests. The published field MSW hydraulic conductivities are found to be higher than the laboratory results. Landfilled MSW possesses lower hydraulic conductivity than fresh MSW due to increased finer particles resulting from degradation. The decreasing hydraulic conductivity with increasing dry unit weight is expressed by an exponential decay function.     

Preparation of high molecular weight genomic DNA from nuclei of woody plants

We have developed a rapid and reliable method for preparation of high molecular weight genomic DNA from sweet orange (Citrus sinensis) suitable for subsequent digestion by rarely cutting restriction enzymes and then separation by pulsed-field gel electrophoresis (PFGE). Methods previously described for preparation of plant DNA prior to PFGE involved protoplast isolation, a procedure that can be inefficient and time-consuming for several plant species. Nuclei isolated from plant tissues were embedded into agarose blocks and treated to release DNA, which was cleaved by restriction enzymes and then submitted to PFGE. One gram of fresh leaves gave approximately 15 micrograms of high molecular weight genomic DNA (> 2000 kbp). Within-gel hybridizations were used instead of classical Southern blotting, and the resulting signals were adequate when they were compared with those obtained with DNA prepared from crude ground leaf tissues.     

Conductometric determination of CO2 in air samples

A new procedure enables the CO2 concentrations of air samples to be determined and automatically registered. The CO2 contents of the air samples are absorbed in an Sr(OH)2 solution. The resulting decrease in electrical conductivity of the solution is automatically registered by a d.c. strip-chart recorder in such a way that the decline of the curve is proportional to the amount of CO2 absorbed. In each analysis, quantities of CO2 up to about 8 mumol can be determined with an error of less than 0.02 mumol, and, accordingly, CO2 quantities of 2 to 8 mumol contained in samples of at least 150 ml of fresh atmospheric air or about 1 ml of carboxygen or expired air can be analysed with an accuracy of better than +/- 1.0% of their CO2 content.     

Structure at 0.85 A resolution of an early protein photocycle intermediate

Protein photosensors from all kingdoms of life use bound organic molecules, known as chromophores, to detect light. A specific double bond within each chromophore is isomerized by light, triggering slower changes in the protein as a whole. The initial movements of the chromophore, which can occur in femtoseconds, are tightly constrained by the surrounding protein, making it difficult to see how isomerization can occur, be recognized, and be appropriately converted into a protein-wide structural change and biological signal. Here we report how this dilemma is resolved in the photoactive yellow protein (PYP). We trapped a key early intermediate in the light cycle of PYP at temperatures below -100 degrees C, and determined its structure at better than 1 A resolution. The 4-hydroxycinnamoyl chromophore isomerizes by flipping its thioester linkage with the protein, thus avoiding collisions resulting from large-scale movement of its aromatic ring during the initial light reaction. A protein-to-chromophore hydrogen bond that is present in both the preceding dark state and the subsequent signalling state of the photosensor breaks, forcing one of the hydrogen-bonding partners into a hydrophobic pocket. The isomerized bond is distorted into a conformation resembling that in the transition state. The resultant stored energy is used to drive the PYP light cycle. These results suggest a model for phototransduction, with implications for bacteriorhodopsin, photoactive proteins, PAS domains, and signalling proteins.     

Chronic congestive heart failure. Description and survival of 190 consecutive patients with a diagnosis of chronic congestive heart failure based on clinical signs and symptoms

The malaria parasite life cycle presents several targets for attack, but these different parts of the life cycle are susceptible to different types of host immune response. For example, the sporozoite is most sensitive to immune antibody, while liver stage parasites can be eliminated by cytotoxic T lymphocytes. Attachment of merozoites to erythrocytes, on the other hand, can be blocked by antibody. Convincing experimental evidence shows that completely protective immunity to malaria can be induced. The challenge now is to design recombinant or synthetic vaccines that induce the right types of immune responses to specific life cycle stages. This requires the identification and characterization of B- and T-lymphocyte epitopes expressed by the parasite or by parasitized host cells. These epitopes must be incorporated into a delivery system that maximizes the interaction between the vaccine epitopes and the host immune system. Many epitopes from several parts of the life cycle are already characterized; development of multivalent vaccines, that is, vaccines which contain immunogens from more than one part of the life cycle, is a promising area for research efforts.     

A novel family of compression algorithms for ECG and other semiperiodical, one-dimensional, biomedical signals

In this paper, a novel family of compression algorithms is presented, which is designed to exploit the redundancy of one-dimensional (1-D) semiperiodical biomedical signals resulting from the cyclic nature of the underlying physical process. The basic idea is that a pool of past-seen cycles is maintained and cycles to be encoded can be stored as transformed versions of those residing in the pool. Conceptually, this approach is an extension of dictionary-based coding schemes used for text compression to signal patterns residing in an n-dimensional space. A cycle transformation method is introduced in order to render the pattern matching process practical and to enable cycle substitution. Based on the principles of the algorithmic family and this transformation method, an electrocardiogram (ECG)-oriented algorithm is implemented and thoroughly tested. The performance of this implementation is examined theoretically and deductions about the optimal algorithm settings are made. The ECG compression algorithm is superior to the average beat subtraction algorithm as proposed by Hamilton and Tompkins in cases where high compression ratios are required.