[Effects of litter thickness on natural regeneration of Larix principis-rupprechtii plantations]. / 枯落物厚度对华北落叶松人工林天然更新的影响.

In this study, we explored the thickness influence of undecomposed litter layer and semi-decomposed litter layer on the natural regeneration in an artificial pure forest of Larix principis-rupprechtii in the forest area of Guandi Mountain. We divided the litter into an undecomposed layer and a semi-decomposed layer, which was further divided into eight groups based on the thickness. The results showed that when the thickness of undecomposed layer was 0.32-0.83 cm, and that of semi-decomposed layer was 0.18-0.89 cm, the regeneration index was larger (≥0.15), and the regeneration was better. When the thickness of undecomposed layer was more than 1.1 cm and that of semi-decomposed layer was more than 0.5 cm, the regeneration index was smaller (≤0.07), and the rege-neration of understory was worse. Results of redundancy analysis showed that the undecomposed layer thickness of litter had a high and stable explanatory ability for natural regeneration, with a contribution rate of 38.7%, while the semi-decomposed layer thickness had no significant effect on natural regeneration. Structural equation modeling revealed that the thickness of undecomposed layer of litter increased the mechanical resistance to seed germination which had a negative direct effect on natural regeneration (-0.617), and a positive indirect effect on natural rege-neration by influencing the content of alkali-hydrolyzed nitrogen and available phosphorus (+0.178). The combined effects (-0.439) showed an inhibitory effect on the natural regeneration. In conclusion, the thickness of undecomposed layer of litter under L. principis-rupprechtii was most closely related to natural regeneration, and the thickness of semi-decomposed layer had a minimal effect on natural regeneration.

Root distribution characteristics of monoculture and mixture of Pinus tabuliformis and Robinia pseudoacacia plantation.

In this study, we analyzed the vertical distribution characteristics of root biomass density, root length density, root surface area density in monoculture and mixture of Pinus tabuliformis and Robinia pseudoacacia plantations in Caijiachuan small watershed of Jixian County, Shanxi. We examined their relationships with soil physical and chemical properties in different stand types. The results showed that the total root biomass density of P. tabuliformis and R. pseudoacacia in mixture was more than 75% higher than that in monoculture. Root system of P. tabuli-formis mainly distributed in shallow layer (0-40 cm), while that of R. pseudoacacia was deeper (40-80 cm). Fine roots were predominant in different diameter classes. Length density and surface area density of fine roots were in the order of R. pseudoacacia in mixture > P. tabuliformis in mixture > R. pseudoacacia stand > P. tabuliformis stand. Root biomass density of fine roots was in the order of P. tabuliformis in mixture ＞ R. pseudoacacia in mixture ＞ P. tabuliformis stand ＞ R. pseudoacacia stand. In vertical profile, the total root and fine root biomass, root length and root surface area density of P. tabuliformis stand, R. pseudoacacia stand, P. tabuliformis in mixture and R. pseudoacacia in mixture showed a rule of decreasing with the increases of soil depth. Under different stand types, fine root length density, root biomass density and total root length density were positively correlated with soil total nitrogen, soil organic carbon, and soil water contents. Total root surface area density was significantly positively correlated with soil organic carbon, soil water content, and soil total nitrogen. The distribution of roots in pure and mixed stands of P. tabuliformis and R. pseudoacacia showed different patterns. Compared with the pure stand, the mixed stand had higher root biomass, soil nutrient contents, and soil water content.

[Natural regeneration of Larix principis-rupprechtii plantations with different densities and its influencing factors]. / ä¸åŒå¯†åº¦åŽåŒ—è½å¶æ¾æž—å¤©ç„¶æ›´æ–°åŠå ¶å½±å“å› å­.

In this study, we analyzed the natural regeneration of Larix principis-rupprechtii pure plantations with stand densities of 128, 240, 320, 400, 480, 560, 640 and 720 trees·hm-2 in the Guandi Mountains and its influencing factors. The results showed that the regeneration index first increased and then decreased with the increases of stand density, and that the regeneration performance of stand with medium density (400-560 trees·hm-2) was significantly better than other stands. Light conditions, herbaceous plants and litter of the understory had a dual effect on the regeneration of L. principis-rupprechtii. Excessive light, herbaceous plant cover or over-thick litter was not instrumental to the regeneration. Soil organic matter promoted stand regeneration by providing soft soil texture, adequate water content, low phosphorus but high nitrogen. The effects of the examined factors on the regeneration index were as follows: soil water content (0.798) > total nitrogen (0.621) > litter thickness (-0.597) > soil porosity (0.504) > soil organic matter (0.493) > total phosphorus (-0.404) > transmitted total light (-0.274) > herbaceous plants cover (-0.021). In the plantation management, stand density could be controlled at about 480 trees·hm-2 by thinning or replanting, while litter could be cleared properly to improve soil condition and to promote natural regeneration of L. principis-rupprechtii.

Case report: Leukemia cutis as the first manifestation of chronic neutrophilic leukemia in a 6-year-old girl.

Chronic neutrophilic leukemia (CNL) is a rare BCR-ABL negative myeloproliferative neoplasm that usually affects older adults with a poor prognosis. Leukemia cutis is an extramedullary manifestation of leukemia and may be misdiagnosed by dermatologists. Here, we describe a case of CNL in a 6-year-old Chinese girl with leukemia cutis as the first manifestation. Her skin rashes failed to attract the attention of dermatologists in early stages. The diagnosis was confirmed by peripheral smear, bone marrow studies, genomic analysis and skin biopsy.

Evaporative characteristics of sessile nanofluid droplet on micro-structured heated surface.

Micro-structure patterned substrates attract our attention due to the special and programmable wettabilities. The interaction between the liquid and micro/nano structures gives rise to controllable spreading and thus evaporation. For exploration of the application versatility, the introduction of nanoparticles in liquid droplet results in interaction among particles, liquid and microstructures. In addition, temperature of the substrates strongly affects the spreading of the contact line and the evaporative property. The evaporation of sessile droplets of nanofluids on a micro-grooved solid surface is investigated in terms of liquid and surface properties. The patterned nickel surface used in the experiments is designed and fabricated with circular and rectangular shaped pillars whose size ratios between interval and pillars is fixed at 5. The behavior is firstly compared between nanofluid and pure liquid on substrates at room temperature. For pure water droplet, the drying time is relatively longer due to the receding of contact line which slows down the liquid evaporation. Higher concentrations of nanoparticles tend to increase the total evaporation time. With varying concentrations of graphite at nano scale from 0.02% to 0.18% with an interval at 0.04% in water droplets and the heating temperature from 22 to 85°C, the wetting and evaporation of the sessile droplets are systematically studied with discussion on the impact parameters and the resulted liquid dynamics as well as the stain. The interaction among the phases together with the heating strongly affects the internal circulation inside the droplet, the evaporative rate and the pattern of particles deposition.

Actuation of adaptive liquid microlens droplet in microfluidic devices: A review.

A significant growth of research on adaptive liquid lens is achieved over the past decades, and the field is still attracting increasing attentions, focusing on the transition from the current stage to the commercialized stage. The challenges faced are not limited to fabrication, material, small tuning range in focal lengths, additional control systems, limitations in special actuation methods and so on. In addition, the use of external driving parts or systems induce extra problem on bulky appearance, high cost, low reliability etc. Therefore, adaptive liquid lens will be an interesting research focus in both microfluidics and optofluidics science. This review attempts to summarize and focus on the droplet profile deformation under different driving mechanisms in tunable liquid microlens as well as the application in cameras, cell phone and so on. The driving techniques are generally categorized in terms of mechanisms and driving sources.

Clinical Characteristics of Bloodstream Infections in Pediatric Acute Leukemia: A Single-center Experience with 231 Patients.

BACKGROUND: Acute leukemia is the most common pediatric hematological malignancy. Bloodstream infections (BSIs) are severe complications in these patients during chemotherapy. This study aimed to explore the clinical presentation and etiology of BSI, as well as the common sites of infection, and to provide a basis for the rational regarding antibiotic use. METHODS: We performed a retrospective chart review of all pediatric patients who had acute leukemia accompanied by a BSI in our hospital from December 2011 to September 2015. All patients were selected based on clinical presentation and had to have at least one positive blood culture for inclusion. The basic clinical characteristics, blood culture results, and antimicrobial susceptibilities were analyzed. RESULTS: All 231 patients had a fever; of them, 12 patients continued to have a fever. Twenty-five patients had nonremitting (NR) leukemia, and 206 patients achieved complete remission (CR). Differences in the duration of fever between the NR and CR groups were significant (9.6 ± 7.9 vs. 5.1 ± 3.8 days, P= 0.016). One hundred and eighty patients had agranulocytosis. Differences in fever duration between the agranulocytosis and nonagranulocytosis groups were significant (6.2 ± 5.1 vs. 4.1 ± 2.6 days, P= 0.001). The other sites of infection in these 231 patients were the lung, mouth, digestive tract, and rectum. Blood culture comprised 2635 samples. There were 619 samples, which were positive. Of the 619 positive blood culture samples, 59.9% had Gram-negative bacteria, 39.3% had Gram-positive bacteria, and 0.8% had fungus. The primary pathogens were Pseudomonas aeruginosa, Enterobactercloacae, Escherichia coli, and Klebsiella pneumoniae. Of these 231 patients, 217 patients were cured. The effective treatment ratio was 94%. CONCLUSIONS: Gram-negative bacteria were the main pathogenic bacteria in patients with acute leukemia in our center. NR primary illness, agranulocytosis, and drug-resistant pathogenic bacteria were all risk factors for poor prognosis.

[Circulating galactomannan screening for early diagnosis and treatment of invasive aspergillosis].

OBJECTIVE: To explore the value of circulating galactomannan (GM) screening for early diagnosis and treatment monitoring of invasive aspergillosis (IA). METHODS: Serum samples from 141 IA patients for the detection of GM by Platelia Aspergillus (Bia-Rad) were collected before and after systematic anti-fungal therapy. RESULTS: (1) An increase in the clinical diagnosis rate of IA was obtained on the result of GM detection. The GM positivity appeared (10+/-4.1) (8-15) d before positive sputum culture, while (12.6+/-5.7) (6-22) d before the CT positive image. (2) Among the 62 patients with consecutive serum samples, 50 were success in treatment and 12 died. A progressive decrease of GM level was found in the former group, while the rising antigen titres were found in the latter. CONCLUSION: Compared with other diagnostic test, GM test has an obvious advantage of higher positivity and earlier result. The anti-fungal effectiveness can be estimated by dynamic detection of serum GM.

[A preliminary investigation on early diagnosis of invasive aspergillosis in patients with blood diseases by using circulating galactomannan test].

The objective of this study was to explore the useful value of circulating galactomannan (GM) for early diagnosis of invasive aspergillosis. All 141 patients were classified as 103 patients of clinical and possible diagnosis, and 38 non-Aspergillus patients. 209 serum samples for the detection of GM by Platelia Aspergillus were collected before anti-fungal vaccine therapy. ELISA method was used in detection of GM. The results showed that (1) the sensitivity of 87.5%, specificity of 81.6%, positive prediction of 66.7% and negative prediction of 93.9% were determined by using cut-off value. According to the result of ELISA, the clinical diagnosed patients was up to 48, while the possible diagnosed patients were 55. (2) Among 62 patients with consecutive examinations of serum samples, 50 patients were successfully diagnosed and treated, while 12 patients died. A progressive reduction of GM level was found in survivors, however, the patients of poor prognosis showed higher antigen titres. It is concluded that GM test has more significance for earlier diagnosis of aspergillosis, the concentration of GM is related to prognosis of disease.