[The preservation capacity of water and fertility of soilless cultivation substrate for Panax quinquefolium L.)]

The preservation capacity of water and fertility of several soilless cultivation substrates for Panax quinquefolium was compared in a large area. The data indicate that vermiculite mixed with sand (volume 1:1) is the most suitable soilless substrate for P. quinquefolium, for it is loose and features good preservation of fertility, water retaining, drainage, and air permeability. Timely analysis of nutrient contents in the substrates during cultivating period may serve as a guideline for correct application of fertilizer.

An MRI perfusion model incorporating nonequilibrium exchange between vascular and extravascular compartments

A model of MRI signal intensity which is a function of perfusion is developed based upon the assumption that biological tissue can be represented by a blood and tissue compartment. The longitudinal magnetization is derived from the Bloch equations which are modified to model the magnetization in both the blood and tissue as a function of the following physiological parameters: blood flow velocity; perfusion fraction, which in the model is parameterized in terms of the ratio of the cross-sectional areas of the tissue and blood compartments; diffusion; rate of exchange between the blood and extravascular tissue compartments. Simulations of slice profiles excited by a repetitive sequence of 90 degrees slice-selective pulses show that the signal intensity in the blood and tissue compartments are modulated by the physiological parameters. A key factor in the modulation of the MRI signal is a time-of-flight effect whereby unexcited spins perfuse the excited region and exchange with blood and tissue compartments, thus immediately increasing the slice signal intensity but also delaying the spin exits from the slice, thereby decreasing their contribution to slice signal intensity in future repetitive pulse measurements.

[Clinical uses of digital subtraction arthrography of the temporomandibular joint]

In the present study, digital subtraction arthrography of TMJ upper cavity was performed in 20 cases with TMJ dysfunction syndrome. It was found that digital subtraction arthrography of TMJ can eliminate various overlapping imaging interference of skull components and has great diagnostic value for TMJ dysfunction syndrome, especially for the diagnosis of small meniscus perforation and the location of meniscus perforation. If this technique can be combined with dynamic observation of TMJ arthrography, the diagnoses for various displacement of meniscus can be made more exactly. However, it is impossible to carry out dynamic observation for TMJ when we use this technique only. This is its disadvantage. Therefore, the best way is to combine arthrographic dynamic observation or arthrographic fluoroscopic observation with digital subtraction arthrography.

[Effects of sodium molybdate on guinea pig atria contractility]

Sodium molybdate (Mo) 10-1000 mumol/L markedly reduced the contratile force of left atria isolated from guinea pig. Mo 100 mumol/L obviously reduced the heart rates in right atria, markedly prolonged the functional refractory period from 185 +/- 12 to 245 +/- 4 ms and inhibited the resting potentiation. Mo 100 and 300 mumol/L reduced the frequency-dependent positive staircase phenomenon. However, verapamil 25 mumol/L reversed the frequency-dependent positive staircase phenomenon to negative one. The mechanism can be explained by the effect on Ca2+ movement in the heart atrium.

[Effects of concentration and ratio of N, P and K on seedlings of Panax quinquefolium L]

Results of the orthogonal experiment of N, P and K are as follows: (1) The highest growth rate occurs in treatment 4 (N100ppm, P25ppm, K250ppm) and other features are also good. So this treatment can be used in hydroponics of seedling of P. quinquefolium. (2) The influences of N, P and K concentration on the contents of ginsenosides in different parts of seedling are different. The content of ginsenosides in aerial part is 14.72-16.72%, higher than 3.24-4.00% in root.

Reflectance diagram-aided technique for optical coating design and monitoring

An amplitude reflectance diagram is a useful tool for visualizing the relationships between the performance of an optical coating and the optical parameters. This paper gives a brief description of the construction and characterization of the reflectance diagrams for different indices. Then, applications of reflectance diagramaided techniques to the design of both phase dispersion-induced narrow reflection and transmission filters, as well as to the optical monitoring of the symmetric multilayers of types (A2BA) and (AB2CBA), are illustrated. Some experimental results of phase dispersion-induced narrowband filters are reported.

Apolipoprotein A-I and A-II levels in an Australian population

Values for apolipoproteins A-I and A-II (apo A-I and apo A-II) are reported for 389 women and 390 men in the town of Busselton, Western Australia. Apo A-I levels were found to be relatively constant with age in men but to rise with age in women. Apo A-II levels remained constant with age in men until older age, when they declined, but rose with age in women, showing a fall in the oldest age group. Apo A-I levels were greater in women than in men, but apo A-II levels were lower in younger women than in younger men, and higher in older women than in older men. On stepwise multiple regression analysis, neither apo A-I nor apo A-II levels showed an independent relationship with age in women; the same was true for apo A-I in men. Alcohol consumption was directly associated with apo A-I and A-II levels in both sexes; adiposity was inversely associated with apo A-I levels in both sexes but with apo A-II only in women. Triglyceride levels showed an inverse association with apo A-II in women. Frequency of exercise was independently and directly associated with apo A-I and A-II levels in women only.

Contemporary rural-urban migration of the Chinese population

The author examines rural-urban migration in China. "The present article provides an estimate of the volume of this population flow since 1949, based on a survey of population flow statistics from 74 cities, and discusses the theories and policies on migration."

Study of different phases in growth cycle of human bone marrow cells and their growth speed, using rat-human cell hybridization, premature chromosome condensation, and sister chromatid differentiation techniques

The cytokinetic activity of bone marrow cells is an indication of hemopoietic status. In the routine examination of bone marrow smears, only M phase can be identified, whereas the different phases of the remainder of the cell cycle are not possible to determine. However, by using premature chromosome condensation and bromodeoxyuridine differential staining techniques, cell stage and cell kinetics can be easily determined. Ninety-eight samples of human bone marrow were collected, cells were hybridized with mitotic M3 cells, and 5016 randomly selected hybrid cells were analyzed for cell stage. Our data demonstrated that 80.37% of the cells were in G1 phase, 12.66% were in S phase, 5.29% were in G2 phase, and 1.68% were in M phase. In specimens that had been cultured for 48 h in the presence of bromodeoxyuridine, 57.46% had completed at least two rounds of DNA replication. In 72-h specimens, 69.27% of the cells had completed at least two S phases. In 96-h specimens, 2S and 2S+ cells occupied 74% of the cell population. The use of cell hybridization techniques, premature chromosome condensation, and bromodeoxyuridine-dependent differential staining revealed the phases of the cell cycle distinctly, as well as the kinetics of cell growth.

[Carcinoembryonic antigen assay in serum and pleural effusion of pulmonary malignancies and benign lesions]

Levels of carcinoembryonic antigen(CEA)in the serum and pleural effusion in malignancies (65) and benign (25) of lung were determined. There are 20 cases of adenocarcinoma, 16 undifferentiated carcinoma, 7 squamous cell carcinoma, 4 alveolar carcinoma, 12 unclassified carcinoma, 1 polymorphous adenoma, 1 mesothelioma, 1 thymoma, 1 metastatic cancer from kidney and 2 metastatic breast cancer. In the benign lesions, there are 20 tuberculosis, 2 heart failure, 1 pneumonia, 1 empyema and 1 cirrhosis. The mean of the CEA level in the serum of lung cancer group was 12.63 ng/ml as compared with that of the tuberculosis group, 3.01 ng/ml (P less than 0.01). The level of CEA in pleural fluid in the lung cancer group was 57.30 ng/ml as compared with that of tuberculosis group, 5.55 ng/ml (P less than 0.01). The content of CEA in the serum and pleural fluid in lung cancer group was remarkably different (P less than 0.01). CEA level in the serum of adenocarcinoma is the highest (mean 15.51 ng/ml). If we set 5 ng/ml as the margin of normal CEA level in serum, the positive rate for cancer would be 54.2%. It is suggested that the margin of CEA normal value be set at 10 ng/ml for the pleural fluid. Higher readings may imply cancer.

Analysis of mouse major urinary protein genes: variation between the exonic sequences of group 1 genes and a comparison with an active gene out with group 1 both suggest that gene conversion has occurred between MUP genes

Here we compare the exonic sequences of four Group 1 mouse major urinary protein (MUP) genes and four Group 1 cDNA sequences. These define seven different nucleotide sequences which differ from each other by 0.35% of bases on average, and which would code for seven different MUP proteins that could probably be resolved physically into at least five classes. The sequences differ at 13 nucleotide positions and at six codons, and although they are closely related their descent cannot be described by a simple series of duplications. We also describe the sequence of another liver cDNA (pMUP15) which has diverged from the Group 1 consensus sequence in 14.6% of bases. The divergence is much greater over exons 1-3 than over exons 4-6, suggesting that an ancestral gene conversion event has occurred. pMUP15 also differs from the Group 1 genes in having a longer signal peptide sequence and a different splice configuration between exons 6 and 7. Unlike the Group 1 sequences, pMUP15 contains a potential N-linked glycosylation site. Other published work has shown that a shorter cDNA clone which is identical over their common sequence to pMUP15 codes for MUP proteins that are unusually large in size and acidic in pI. We show here that mouse urine does indeed contain a glycosylated MUP protein with those properties, presumably the product of the gene that corresponds to pMUP15.

Synthesis of simian virus 40 chromosomes in nuclear extracts from dihydroxyanthraquinone-treated cells

The effect of dihydroxyanthraquinone (DHAQ), a new antitumor drug, on mammalian chromosome replication was investigated using simian virus 40 (SV40) as a model system. The maximum effect of inhibition on viral DNA synthesis was observed within 30-40 min after the addition of the drug. The extent of inhibition of viral DNA synthesis appeared to be directly related to the number of viral replicons which interact with DHAQ molecules in vivo. No apparent strand breakage of SV40 DNA was observed in infected cells treated with DHAQ ranging from 0.3 to 10 microM. However, strand breakage was induced upon cell lysis presumably by released nuclease. Repair of the damaged SV40 chromosomes in vitro resulted in the synthesis of completed supercoiled SV40 DNA. This repair synthesis was mostly confined to the region containing the replication origin of SV40 DNA as judged by the digestion of DNA with restriction endonucleases HindII and HindIII. Since SV40 DNA sequences close to the origin of replication are not complexed with histones to form a nucleosome structure, the results suggested that DHAQ may disturb chromosome structure by interacting preferentially to the nucleosome-free regions and causing the aberrant gene duplication and expression.