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An unprecedented 19-membered allenic macrolide archangiumide (

This study aims to evaluate the diagnostic value of percutaneous core needle biopsy (PCNB) in diagnosing acral bone tumors. The clinical PCNB data of 341 patients with bone tumors were retrospectively analyzed. The diagnostic accuracy was calculated according to the lesion components (sclerotic, parenchymatous, or cystic), benign or malignant character, and whether a soft tissue mass was present. The chi-square test was performed to assess diagnostic accuracy. The accuracy rate for sclerotic and substantive lesions was high (87.5% and 90.1%, respectively), while that for cystic lesions was the lowest. The accuracy difference in diagnosing benign and malignant lesions was significant (P

As a modern city’s “fourth dimension space”, UTLT is a typical narrow and confined underground space. Due to the special structural position and the curvature of the tunnel, the hot smoke in the fire field can easily form a “smoke turning circle” phenomenon, which greatly reduces environmental visibility and threatens people escape quickly. This article takes a UTLT small radius tunnel as an example to investigate the relationship between the curvature of the tunnel and the visibility of the fire near the fire source. Firstly, using Pyrosim to simulate the change of visibility in different curvatures of fire field, and using SPSS to carry out multiple regression analysis on numerical simulation data, summarizing the prediction model of the impact of small radius UTLT tunnel curvature on the visibility near the fire source. Finally, regression model analysis and test show that the curvature is negatively correlated with the visibility of the tunnel and the prediction model is feasible. The research results can provide theoretical guidance for the design of UTLT-type small-radius circulation smoke evacuation and rapid evacuation of personnel, and provide a reference for similar curve tunnel curvature design and smoke control measures.

Determining the combustion characteristics of combustibles in high-speed trains is the foundation of evaluating the fire hazard on high-speed trains scientifically, and establishing effective active and passive fire precautions. In this study, the double seats in the compartments of CRH1 high-speed trains were used as the main research object. Under different test conditions, including the power of ignition sources and ventilation rates, full-scale furniture calorimeter tests were conducted to study important fire combustion characteristics such as the ignition characteristics of seats, heat release rate, mass loss rate, total heat release, temperature variation, and smoke release rate. The relationships among these parameters were analyzed and summarized into combustion behavior and characteristics, thus providing fundamental data and reference for the development of fire precautions and safety design of high-speed trains. The results in this test are as follows: (i) The double seats of high-speed trains are relatively easy to ignite and susceptible to the fire ground environment. (ii) The combustion temperature in the test apparatus exceeded 600°C in only 2min for the larger ignition source. (iii) The heat release rate exceeded 800kW. (iv) The total heat release resulted mainly from flame combustion. (v) The final mass loss rate was ∼30%. (vi) The lowest light transmittance was

Urban traffic link tunnels (UTLT) have a complex design and are a significant fire hazard. Due to the circular nature of the tunnels, smoke can easily spread through the tunnel during a fire and form a circulation loop, severely hampering safe evacuation and rescue. In this paper, the 2.8km long UTLT in Sichuan, China's Dayuan central business district (CBD) was the study subject. Fire dynamics and similarity theory were employed to perform theoretical calculations and numerical simulations targeting four different mechanical smoke extraction methods under typical fire conditions. Smoke movement was quantitatively analyzed, thus determining which of the four plans was the optimal smoke control technique: semi-transverse ventilation combined with sinking-courtyard air compensation, with ventilation beginning in the fire zone and the two flanking smoke control zones at a rate of 20 ventilations/hour. Our result provides a theoretical basis for designing and running a smoke control system in relevant projects at home and abroad, and serves as both a theoretical and a constructive practical ground for formulating regulations related to UTLT.

Duanwang Coal Mine is located at north of Qinshui coalfield in Shanxi province, China, which gently inclined and thick seams have been mined. Authorized production capacity of the coal mine is 1.8Mt/a. With the increase of mining depth, the mine gas emission quantity increased. Karst collapse columns are very developed in the minefield, and the phenomenon of abnormal gas emission always occurred at the coal face and driving gateway around the collapse columns, then the mine became high gassy one from low gassy mine. Using field measurement and theoretical analysis methods, the following conclusion can be drawn. Karst collapse columns have significant influences on gas emission of the coal face and driving gateway. Here are large amount of free form gas into and around the collapse columns, the collapse columns were disclosure while driving gateway, a large amount of the free gas into collapse column would be instantly released, which caused abnormal gas emission at driving gateway, even leading to gas density exceeding limitation by Coal Mine Safety Regulation of China. However, during mining area of the collapse columns, gas emission quantity at coal face was relatively smaller.

The underground space, also known as the "fourth dimension" of the city, reflects the efficient use of urban development intensive. Urban traffic link tunnel is a typical underground limited-length space. Due to the geographical location, the special structure of space and the curvature of the tunnel, high-temperature smoke can easily form the phenomenon of "smoke turning" and the fire risk is extremely high. This paper takes an urban traffic link tunnel as an example to focus on the relationship between curvature and the temperature near the fire source, and use the pyrosim built different curvature fire model to analyze the influence of curvature on the temperature of the fire, then using SPSS Multivariate regression analysis simulate curvature of the tunnel and fire temperature data. Finally, a prediction model of urban traffic link tunnel curvature on fire temperature was proposed. The regression model analysis and test show that the curvature is negatively correlated with the tunnel temperature. This model is feasible and can provide a theoretical reference for the urban traffic link tunnel fire protection design and the preparation of the evacuation plan. And also, it provides some reference for other related curved tunnel curvature design and smoke control measures.

Cotyledon segments derived from zygote embryos of mango (Mangifera indica L. cv. Zihua) were cultured on agar medium for 28 days. Depending on different pre-treatments with plant growth regulators, two distinct patterns of adventitious roots were observed. A first pattern of adventitious roots was seen at the proximal cut surface, whereas no roots were formed on the opposite, distal cut surface. The rooting ability depended on the segment length and was significantly promoted by pre-treatment of embryos with indol-3-acetic acid (IAA) or indole-3-butyric acid (IBA) for 1 h. A pre-treatment with the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) completely inhibited adventitious root formation on proximal cut surfaces. A second pattern of roots was observed on abaxial surfaces of cotyledon segments when embryos were pre-treated with 2,700 μM 1-naphthalenacetic acid (NAA) for 1 h. Histological observations indicated that both patterns of adventitious roots originated from parenchymal cells, but developmental directions of the root primordia were different. A polar auxin transport assay was used to demonstrate transport of [3H] indole-3-acetic acid (IAA) in cotyledon segments from the distal to the proximal cut surface. In conclusion, we suggest that polar auxin transport plays a role in adventitious root formation at the proximal cut surface, whereas NAA levels (influx by diffusion; carrier mediated efflux) seem to control development of adventitious roots on the abaxial surface of cotyledon segments.

Dissoluble manganese supramolecule containing rhodamine 6G luminescent particles (M2) are synthesized, based on dissoluble manganese supramolecule (M1) doping rhodamine 6G (R.6G), by crystalline method. The particle diameters of M1 and M2 determined by ETM are both of micron degree. M1 and M2 can emit solid substrate room temperature phosphorescence (SS-RTP) on filter paper. The transition probability from the singlet state (S1) to triplet state (T1) of the luminescent molecules was greatly enhanced, based on the increment of luminescent molecules for each spot and the heavy atom effect of certain amount of Pb2+. As a result, the phosphorescence intensity (Ip) of M2 was increased sharply, and the enhancing value of phosphorescence intensity (ΔIp) is directly proportional to the concentration of Pb2+. Thus, a new method of SS-RTP enhancing for the determination of trace lead is established based on manganese supramolecule containing rhodamine 6G luminescent particles. The linear range of this method is 0.0040–0.400 pg spot−1 of Pb2+ (corresponding concentration, 0.01–1.0 ng mL−1; sample volume, 0.4 μL spot−1), with a detection limit (LD) of 0.0011 pg spot−1 (corresponding concentration, 2.8 × 10−12 g mL−1 of Pb2+, n = 11). For the working solutions containing 0.0040 and 0.40 ng mL−1 of Pb2+, they were determined repeatedly for seven times, respectively. The R.S.D.s were 3.2 and 3.8%, respectively. This method has good repeatability, sensitivity and high precision. It has been applied to the determination of trace lead in human hair and tea samples with satisfactory results.

In order to find high acitivity and low toxicity antitumor drug-lead compounds, 13 novel N1-(2-furanidyl)-N3-(O,O-dialkylphosphonyl aryl (alkyl)methoxy-carbonylmethyl)-5-fluorouracils were synthesized via phase-transferred catalytic reactions of chloroacetyloxyalkyl phosphonates 2 with N1-(2-furanidyl)-5-fluorouracil. The structures of the products were confirmed by 1H NMR, 31P NMR, IR, and MS spectra and elemental analyses. The results of preliminary bioassay showed that the new compounds possess some extent of inhibitory effect against HCT-8 and Bel-7402 cell lines and good fungicidal activities.

Three interpenetrated polymeric networks, {[Co(bpp)(OH-BDC)] · H2O}n (1) [Ni(bpp)1.5(H2O)(OH-BDC)]n (2) and {[Cd(bpp)(H2O)(OH-BDC)] · 2H2O}n (3), have been prepared by hydrothermal reactions of 1,3-bis(4-pyridyl)propane (bpp), 5-hydroxyisophthalic acid (OH-H2BDC), with Co(NO3)2 · 6H2O, Ni(NO3)2 · 6H2O and Cd(NO3)2 · 4H2O, respectively. Single-crystal X-ray diffraction analyses reveal that the three compounds all exhibit interpenetrated but entirely different structures. Compound 1 is a fourfold interpenetrated adamantanoid structure with water molecules as space fillers, in which bpp adopts a TG conformation (T = trans, G = gauche). Compound 2 is an interdigitated structure from the interpenetrated long arms of one-dimensional molecular ladders, while bpp in 2 adopts both TT and TG conformations. Compound 3 is a twofold interpenetrated three-dimensional network from a one-dimensional metal-carboxylate chain bridged by TG conformational bpp. The hydrogen bonding interactions in 1–3 further stabilize the whole structural frameworks and play critical roles in their constructions.

The hydrothermal reaction of Co(NO3)2·6H2O, imidazole 4,5-dicarboxylic acid (H3IDC), and 4,4‘-bipydine (bipy) under different conditions affords two interesting metal−organic compounds, {[Co3(IDC)2(4,4‘-bipy)(H2O)4]·2H2O}n (1) and {[Co3(IDC)2(4,4‘-bipy)3]·6H2O·DMF}n (2), both of which have been structurally characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. Temperature-dependent magnetic susceptibility for 1 and 2 were also studied. The “all-chair” two-dimensional honeycomb networks, structurally analogous to CFx, were linked by the bridging 4,4‘-bipy ligand in compound 1 to give rise to a 2-fold interpenetrated 3D architecture. Compound 2 features a three-dimensional open framework with hexagonal channels, generated from two-dimensional graphene-like layers pillared by 4,4‘-bipy. The simplest cyclic motif of the 2D networks in 1 and 2 is a 24-membered hexagonal ring consisting of six Co(II) cations and six IDC3- trianions.

For the first time, regenerated plantlets were obtained from immature zygotic embryos of mango (Mangifera indica L.) through direct somatic embryogenesis. Pro-embryogenic mass (PEM)-like structures, which are differentiated as clusters of globular structures, were easily induced directly from the abaxial side of cotyledons from immature fruits, 2.0–3.5 cm diameter by a 2-wk culture period on a modified Murashige and Skoog medium with 5 mgl−1 (25μM) indole-3-butyric acid (IBA). Conversion of somatic embryos into plantlets was achieved after 4 wk of culture on the conversion medium containing 5mgl−1 (23 μM) kinetin. Secondary somatic embryogenesis could also be obtained directly from the hypocotyls of mature primary somatic embryos cultured on the conversion medium. In our experimental system, only minor problems were noted with browning of cultures.

To study the prevalence of 16S rRNA methylase genes in extended-spectrum-lactamascs (ESBLs)-producing Enterobacteriacea, and the correlations of 16S rRNA methylase genes with anminoglycoside resistnace.Seventy-four ESBLs-producing Enterobacteriacea stains were isolated from urinary tract infections. Minimal inhibitory concentrations (MICs) of 5 aminoglycosides against the ESBLs-producing Enterobacteriacea were detected by two-fold agar dilution method. PCR amplification and DNA sequencing were used for screening and identifying 16S rRNA methylase genes. The clonality of 16S rRNA methylase gene positive ESBLs-producing Enterobacteriaceae was assessed by multilocus sequence typing (MLST).The bacterial resistant rates to gentamycin, netilmicin, tobramycin,amikacin and isepamicin were 93.4%, 18.4%, 13.2%, 5.3% and 5.3%, respectively. Tweenty-two out of 74 clinical isolates were 16S rRNA methylase genes positive (29.7%), including 18 armA gene and 7 rmtB gene, and 3 strains with both genes. The resistant rates of those 22 strains to gentamycin , netilmicin, tobramycin, amikacin and isepamicin were 100%, 100%, 59.1%, 18.2% and 18.2%, respectively. Among 19 E. coli isolates, seven sequence types (STs) were identified, named as ST117 (12 strains), ST2003 (2 strains), ST3843 (1 strain), ST915 (1 strain), ST844 (1 strain), ST2581 (1 strain) and ST2922 (1 strain). MLST showed that 3 K. pneumoniae isolates were nonclonal.16S rRNA methylase genes were widely distributed in urinary ESBLs-producing Enterobacteriacea, showing obvious relationship with the resistance to aminoglycosides. The therapy of Amikacin or Isepamicin may be considered in UTIs with 16S rRNA gene positive ESBLs-producing Enterobacteriacea.

This study was to compare the marginal adaptation of single crown made of 3 different all-ceramic systems (IPS e.max, In-Ceram alumina, Kavo Everest) in vitro using a light-body silicone supported by a heavy-body silicone material.The crowns were made for 1 extracted maxillary premolar prepared with a 0.8-mm chamfer margin and 6-degree tapered walls by milling. Ten crowns per system were fabricated. The horizontal marginal discrepancies, vertical marginal discrepancies and absolute marginal discrepancies were measured under an optical microscope at 39.2 magnification. The data were analyzed with one-way analysis of variance (ANOVA) using SPSS 13.0 software package.The results showed the mean values for horizontal marginal discrepancies were between 41.1μm and 44.9μm, for vertical marginal discrepancies were between 51.4μm and 71.7μm, and for absolute marginal discrepancies were between 66.2μm and 85.1μm.The horizontal marginal discrepancies, vertical marginal discrepancies and absolute marginal discrepancies of the three all-ceramic crown systems were within the clinically acceptable standard. However, the IPS e.max system and the Kavo Everest System showed a better marginal fit compared with the In-Ceram alumina system.

To understand the changing trends of non-communicable diseases (NCDs) in Xinjiang Production and Construction Corps from 1998 to 2008.A stratified-cluster random sampling based cross-sectional NCDs survey was carried out in 2008, and using the data of NCDs from the health service surveys in 1998 and 2004, in Xinjiang Production and Construction Corps. The prevalence rate of NCDs was standardization according to age proportion of the population being surveyed in 1998.In 1998, 2004 and 2008, the prevalence rates of NCDs in Xinjiang Production and Construction Corps were 17.26%, 25.61%, 24.85% while the Standardized rates of NCDs were 17.26%, 23.54% and 20.49% respectively. The prevalence rates of NCDs were statistically significant different in 35-, 45-, 55- and over 65 age groups in 1998, 2004 and 2008 which showed an consecutive upward trend. The prevalence rates of hypertension, diabetes, cerebrovascular disease, coronary heart disease and chronic obstructive pulmonary disease increased significantly from 1998 to 2008. The prevalence rate of hypertensive disease among 25- age group, diabetes among 35- age group, cerebrovascular disease and coronary heart disease among 45- age groups showed an increasing trend.Cardiovascular and cerebrovascular diseases, together with diabetes were the fastest increasing ones over the past 10 years and becoming the major diseases, making the Xinjiang Production and Construction Corps an aging population. NCDs should be prioritized in the health development plan. Targeted health education should be carried out in the whole population, together with other interventions as well as management programs on chronic diseases to reduce the prevalence of NCDs.

To make an epidemiological investigation on malaria in Motuo County, Linzhi Prefecture of Tibet.In July of the year 2006, the following activities were conducted in 2 selected villages from each of the three townships, i.e., Motuo, Dexing and Beibeng: malaria history survey among inhabitants in recent 2 years; collection of blood samples of inhabitants for examining malaria parasites, IFAT and detecting G6PD, respectively; mosquito collection in human dwellings and cattle shelters at night and various resting sites at day-time; mosquito collection by outdoor human baiting capture; classification and composition calculation of mosquito species and man biting rates; ELISA for detecting sporozoite infection of Anopheles.The mean rate of two-year malaria history was 8.98% (118/1314) and the parasite rate was 3.13% (38/1216, all P. vivax) in the inhabitants. The parasite positive rate among the feverish patients was 7.14% (3/42). IFAT revealed a malaria antibody rate of 40.24% (472/1173). The G6PD deficiency rate was 1.74% (21/1208). Five hundred and thirteen anopheline mosquitoes were caught. They were An. maculatus (474) which occupied 92.4% (474/513), An. peditaeniatus (35), An. kochi (3) and An. sinensis (1). The mean indoor density of An. maculatus was 4.75/night in human houses, and 69.5/night in cattle shelters. The outdoor human biting rate was 22.75/half-night/person, and the sporozoite rate of An. maculatus in anopheline saliva glands was 0 by ELISA.Motuo County is an endemic area of vivax malaria with An. maculatus as the potential vector.

A high efficient protocol of Agrobacterium-mediated transformation of Musa acuminata cv. Mas (AA), a major banana variety of the South East Asia region, was developed in this study. Male-flower-derived embryogenic cell suspensions (ECS) were co-cultivated in liquid medium with Agrobacterium strain EHA105 harboring a binary vector pCAMBIA2301 carrying nptII and gusA gene in the T-DNA. Depending upon conditions and duration of co-cultivation in liquid medium, 0-490 transgenic plants per 0.5 ml packed cell volume (PCV) of ECS were obtained. The optimum duration of inoculation was 2 h, and the highest transformation frequency was achieved when infected ECS were co-cultivated in liquid medium first for 12 h at 40 rpm and then for 156 h at 100 rpm on a rotary shaker. Co-cultivation for a shorter duration (72 h) or shaking constantly at 100 rpm at the same duration gave 1.6 and 1.8 folds lower transformation efficiency, respectively. No transgenic plants were obtained in parallel experiments carried on semi-solid media. Histochemical GUS assay and molecular analysis in several tissues of the transgenic plants demonstrated that foreign genes were stably integrated into the banana genome. Compared to semi-solid co-cultivation transformation in other banana species, it is remarkable that liquid co-cultivation was much more efficient for transformation of the Mas cultivar, and was at least 1 month faster for regenerating transgenic plants.

In this paper, we described the direct somatic embryogenesis from both immature cotyledon cuts and nucelli in the same mango cultivar (Mangifera indica L. var Zihua), studied the effect of growth conditions of embryogenic cultures (EMs) on cryopreservation and compared the cryopreservation response of EMs induced from these two different explants. Histological studies demonstrated that EMs derived from nucelli could be induced directly from epidermal cells of both sides of nucelli, whereas EMs derived from cotyledon cuts were induced only from epidermal cells of the adaxial side of the cotyledons. EMs from either nucelli or cotyledon cuts could be maintained in liquid medium or on solid medium and cryopreserved using a vitrification procedure. Success of cryopreservation of EMs depended on the dehydration treatment and the defined growth conditions during culture but not on their origins. When EMs were sampled during their exponential growth phase in liquid medium and dehydrated with PVS(3) solution for 5 min, survival of the EMs induced from cotyledon cuts and nucelli reached 77.7 and 80%, respectively, after cryopreservation in liquid nitrogen for 24 h. Furthermore, when dehydrated with PVS(3) solution for 30 min, all EMs induced from cotyledon cuts and 96.7% of EMs induced from nucelli could survive after cryopreservation. Cryopreservation did not affect the plant regeneration potential of EMs through somatic embryogenesis. The protocols of somatic embryogenesis and cryopreservation of mango EMs established in this study may offer potential ways to improve mango germplasm conservation and genetic improvement.

Auxin-responsive elements (AuxRE) interact with a new class of plant-specific transcription factors, auxin response factors (ARFs). Some of ARFs have been shown to repress or activate expression of genes with an AuxRE promotor element. In Arabidopsis, ARFs play important roles in early embryo development and vascular strand formation (ARF5), floral patterning (ARF3) and photo- and gravitropic responses (ARF7). Two cut surfaces (distal and proximal) of mango (Mangifera indica L. var. Zi-Hua) cotyledon showed different patterns of adventitious root formation, with only the proximal cut surface, but not the distal one, could be induced to form the roots. Thus, the mango cotyledon is a good system for studying adventitious root formation. A cDNA fragment homologous to the Arabidopsis auxin response factor-like protein and relates to adventitious root formation from the cut sections were isolated using suppressive subtractive hybridization (SSH). Two cDNA clones, designated as MiARF1 (mango auxin response factor 1 gene, GenBank accession number AY255705) and MiARF2 (mango auxin response factor 2 gene, GenBank accession number is AY300808), were identified by 3'RACE. MiARF1, 3 272bp long, contains an open reading frame (ORF) of 2 523bp, 5'UTR of 285bp and 3'UTR of 464bp, MiARF2, 1 474bp long, contains an ORF of 981bp, 5' UTR of 285bp and 3'UTR of 208bp. The deduced MiARF1 and MiARF2 are homologues of auxin response factor (ARF) family of transcriptional regulators, and show high similarity to ARF of Arabidopsis in conserved domains. The motifs of MiARF1 EL-WHACAGPL in DBD (DNA binding domain) and GDDPW in IV domain are identical to that of ARF-like protein of Arabidopsis. MiARF2 is identical to MiARF1 in a large part of DBD, but lacks a carboxyl-terminal domain containing conserved motifs III and IV. Virtual Northern blot showed that the expression of MiARF2 was high in rooting tissue of cultured cotyledon sections but low in non-rooting tissue, and the MiARF1 was expressed both in the rooting and non-rooting tissues. We suggest that the MiARF2 is related to adventitious root formation of mango cotyledon section.

Conventional breeding for dual resistance of disease and pest of Musa cultivars remains a difficult endeavor, as the plant is polyploidic and high in sterility. Biotechnological techniques, eg., genetic engineering, in vitro mutation breeding, or protoplast fusion, may overcome the difficulties and improve the germplasm. Establishment of a stable embryogenic cell suspension (ECS) is a prerequisite for any of the biotechnological breeding methods. In this study an embryogenic cell suspension was established from immature male flower of Musa acuminata cv. Mas (AA), a popular commercial variety of banana in the South-East Asian region. After culture for 5-6 months on callus induction media, which consisted of MS salts, different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), 4.1 micromol/L biotin, 5.7 micromol/L indoleacetic acid (IAA), 5.4 micromol/L naphthaleneacetic acid (NAA), other vitamins, 87 mmol/L sucrose, and solidified with 7 g/L agarose, meristematic globules and yellow, friable embryogenic cultures were induced from the explants of 1-15th row young floral hands of immature male flowers. Of the four treatments of 2,4-D, 9 micromol/L was the most effective on the callus induction, it transformed 40.96% and 7.45% of the cultivated male floral hands into callus and embryogenic callus respectively. The explants to produce highest frequency of the embryogenic calli were floral hands of 6 to 12th rows, which generated 5.79% of the embryogenic calli. Suspension cultures were initiated from these embryogenic calli in liquid medium supplemented with 4.5 micromol/L 2, 4-D. After sieving selection of the cultures using a stainless steel metallic strainer with pore sizes of 154 microm at 15 day intervals for 3 months, homogeneous and yellow embryogenic cell suspensions, composed of single cells and small cell aggregates, were established. Based upon the growth quantity and growth rate of ECS, it was determined that the appropriate inoculum was 2.0 mL PCV ECS/30 mL medium in 100 mL flask, and the appropriate subculture cycle was 15 days. Planting of 6 months old ECS on semi-solid medium of somatic embryo induction and development (MSD) resulted in approximately 280 x 10(3) somatic embryos/mL PCV ECS. MSD contained SH macronutrients, micro-nutrients, Fe-EDTA and MS vitamins supplemented with 4.5 micromol/L biotin, 680 micromol/L glutamine, 2 mmol/L proline, 100 mg/L malt extract, 1.1 micromol/L NAA, 0.2 micromol/L zeatin, 0.5 micromol/L kinetin, 0.7 micromol/L N6-(2-isopentenyl) adenine, 29 mmol/L lactose, 130 mmol/L sucrose and solidified with 2g/L gelrite. After 3 months of maturity on MSD, 17.28% of the somatic embryos were germinated on germination media (MG), consisted of MS salt, Morel and Wetmore vitamins, 0.2 micromol/L 6-BA, 1.1 micromol/L IAA, 87 micromol/L sucrose and solidified with 2 g/L gelrite; and 14.16% of the somatic embryos could develop into normal plantlets on rooting media contained the same composition as that of MG but without auxin and cytokinin.

Three techniques were compared for cryopreserving embryogenic masses (EMs) sampled from mango (Mangifera indica L.) cv. Zihua embryogenic cultures: (i) encapsulation/dehydration; (ii) pregrowth/dehydration; and (iii) vitrification. In all experiments, EMs were sampled from embryogenic cultures during their exponential growth phase and pretreated for 24 h on solid medium containing 0.5 M sucrose before freezing. No recovery was achieved after cryopreservation using the encapsulation/dehydration technique, whatever the moisture content (fresh weight basis) of EMs, which ranged from 78.3% without dehydration to 40.8% after 6 h dehydration. With the pregrowth plus dehydration technique, limited recovery (8.3%) was achieved after desiccation of EMs for 1 h, to 58.5% MC. Using the vitrification technique, recovery ranged from 94.3% after treatment of EMs with the PVS3 vitrification solution for 20 min (EM moisture content of 34.7%) to 10.9% after a 120 min treatment with the vitrification solution (EM moisture content of 26.0%).

Changes in the levels of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC) and polyamines were simultaneously investigated during the early phases of alfalfa somatic embryogenesis. These included the period of induction and subculture of callus, and 3- and 7-day suspension cultures for the induction of somatic embryogenesis. The polyamines contained in the embryogenic callus were found to include putrescine (Put), spermidine (Spd) and spermine (Spm), but the level of Spm was much less than that of Put and Spd. There was a dramatic increase in MACC after induction of embryogenesis, and ACC levels were lower in somatic embryos than in embryogenic callus. Induction of embryogenesis for 3 days increased the levels of ACC and polyamines to a maximum level, and these then reduced as the embryogenesis proceeded. The ratios of Put/Spd and ACC/MACC were decreased during the induction. This indicated that both high levels of ACC and polyamines might be a prerequisite for early differentiation during the induction of the embryogenesis. Thus, there appears not to be competition between polyamine biosynthesis and ethylene biosynthesis at least during the induction of somatic embryogenesis, because both the polyamines and ACC were simultaneously increased during the induction period. Conversion of ACC into MACC and the maintenance of a relatively high level of polyamines, especially Spd, appear to be important for further development of the embryos. When aminooxylvinylglycine (AOA) was added at the initiation of the callus subculture, it had no significant effect on the callus growth, the ethylene production and ACC level of the callus. However, AOA increased the numbers of the embryos accompanying an increase in Spd level and S-adenosylmethionine decarboxylase (SAMDC) activity. Thus, the AOA effect could be associated with Spd increase rather than with the effect of ethylene biosynthesis.

The histological origin of organogenesis was studied during plant regeneration of banana (Musa AAA cv. Williams) via direct organogenesis from micro-cross-sections of the rhizome in modified Murashige–Skoog (MS) medium (including 10 µm 6-BAP, 1 µm IAA and 50 µm KN). The frequency of the organogenesis was dependent on the position from where the explant was cut. Generally, more adventitious shoots were obtained from explants cut from regions close to apical meristem. The origin of adventitious shoots was multicellular, from cell layers with active cell division in the epidermis of the rhizome axis. After 24 h of culture, a layer of epidermal cells close to the leaf sheath base was actively dividing, and as the time in culture increased, regions containing actively dividing cells became enlarged. By the fifth day of culture, regions of actively dividing cells covered the whole peripheral zone of cortex. Several meristemoid structures were formed from the peripheral zone of cortex after 7 days of culture. These structures developed into adventitious shoots by the ninth day of culture. Vigorous plantlets could be regenerated from the shoots when they were transferred to rooting medium containing MS basal salts supplemented with 30 g L–1 sucrose, 6.5 g L–1 agar, a vitamin/amino acid mixture, 1 µm NAA and 1 µm 6-BAP.