[Effects of intercropping and nitrogen application on soil microbial metabolic functional diversity in maize cropping soil.] / çŽ‰ç±³é—´ä½œå’Œæ–½æ°®å¯¹åœŸå£¤å¾®ç”Ÿç‰©ä»£è°¢åŠŸèƒ½å¤šæ ·æ€§çš„å½±å“.

Soil microorganism is an important indicator of soil health and plays a critical role in biogeochemical processes. We collected soil samples from a multi-year in-situ field experiment with two cropping modes (maize monocropping and maize-potato intercropping) subjected to four nitrogen (N) levels (N0, 0 kg·hm-2; N125, 125 kg·hm-2; N250, 250 kg·hm-2; N375, 375 kg·hm-2). By using the Biolog-ECO microplate method, soil microbial metabolic activity, diversity and utilization of six carbon groups were analyzed. The results showed that N application significantly increased the average well color development (AWCD) values, Simpson and Shannon indices, with the highest value at N250 in mono- and inter-cropped soils. Moreover, N application promoted the utilization of amino acids, amines and phenolic compounds, but decreased the utilization of polymers. Compared with monocropping at the same N level, intercropping improved the AWCD values, Simpson and Shannon indices, with a maximal improvement at N250. Intercropping and nitrogen application significantly affected the metabolic activities of the six carbon-source groups. In addition, intercropping improved the utilization of labile carbon sources, such as amino acids and carbohydrates. Results of the redundancy analysis and linear regression showed that intercropping and N application elevated AWCD values by increasing soil temperature, water content, and soil organic carbon content. Therefore, the changes in soil physicochemical properties after intercropping were the main reason for the enhancement of microbial metabolic activity under N application.

Awake fiberoptic intubation and use of bronchial blockers in ankylosing spondylitis patients.

BACKGROUND: Patients with ankylosing spondylitis (AS) combined with severe cervical fusion deformity have difficult airways. Awake fiberoptic intubation is the standard treatment for such patients. Alleviating anxiety and discomfort during intubation while maintaining airway patency and adequate ventilation is a major challenge for anesthesiologists. Bronchial blockers (BBs) have significant advantages over double-lumen tubes in these patients requiring one-lung ventilation. AIM: To evaluate effective drugs and their optimal dosage for awake fiberoptic nasotracheal intubation in patients with AS and to assess the pulmonary isolation effect of one-lung ventilation with a BB. METHODS: We studied 12 AS patients (11 men and one woman) with lung or esophageal cancer who underwent thoracotomy with a BB. Preoperative airway evaluation found that all patients had a difficult airway. All patients received an intramuscular injection of penehyclidine hydrochloride (0.01 mg/kg) before anesthesia. In the operating room, dexmedetomidine(0.5 µg/kg) was infused intravenously for 10 min, with 2% lidocaine for airway surface anesthesia, and a 3% ephedrine cotton swab was used to contract the nasal mucosa vessels. Before tracheal intubation, fentanyl (1 µg/kg) and midazolam (0.02 mg/kg) were administered intravenously. Awake fiberoptic nasotracheal intubation was performed in the semi-reclining position. Intravenous anesthesia was administered immediately after successful intubation, and a BB was inserted laterally. The pre-intubation preparation time, intubation time, facial grimace score, airway responsiveness score during the fiberoptic introduction, time of end tracheal catheter entry into the nostril, and lung collapse and surgical field score were measured. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were recorded while entering the operation room (T1), before intubation (T2), immediately after intubation (T3), 2 min after intubation (T4), and 10 min after intubation (T5). After surgery, all patients were followed for adverse reactions such as epistaxis, sore throat, hoarseness, and dysphagia. RESULTS: All patients had a history of AS (20.4 ± 9.6 years). They had a Willson's score of 5 or above, grade III or IV Mallampati tests, an inter-incisor distance of 2.9 ± 0.3 cm, and a thyromental (T-M) distance of 4.8 ± 0.7 cm. The average pre-intubation preparation time was 20.4 ± 3.4 min, intubation time was 2.6 ± 0.4 min, facial grimace score was 1.7 ± 0.7, airway responsiveness score was 1.1 ± 0.7, and pulmonary collapse and surgical exposure score was 1.2 ± 0.4. The SBP, DBP, and HR at T5 were significantly lower than those at T1-T4 (P < 0.05). While the values at T1 were not significantly different from those at T2-T4 (P > 0.05), they were significantly different from those at T5 (P < 0.05). Seven patients had minor epistaxis during endotracheal intubation, two were followed 24 h after surgery with a mild sore throat, and two had hoarseness without dysphagia. CONCLUSION: Patients with AS combined with severe cervical and thoracic kyphosis should be intubated using fiberoptic bronchoscopy under conscious sedation and topical anesthesia. Proper doses of penehyclidine hydrochloride, dexmedetomidine, fentanyl, and midazolam, combined with 2% lidocaine, administered prior to intubation, can provide satisfactory conditions for tracheal intubation while maintaining the comfort and safety of patients. BBs are safe and effective for one-lung ventilation in such patients during thoracotomy.

[Effects of intercropping on soil nitrification and nitrogen supply in potato field.] / 间作对马铃薯种植土壤硝化作用和硝态氮供应的影响.

Nitrate supply in soils is essential to meet nitrogen (N) demand of crops. However, how intercropping would affect soil nitrate supply and the underlying mechanisms remain unclear. Based on a field experiment of mono- and inter-cropped potato amended with four N application rates (N0, 0 kg·hm-2; N1, 62.5 kg·hm-2; N2, 125 kg·hm-2; N3, 187.5 kg·hm-2), we analyzed the differences in soil nitrate content and intensity, nitrification potential, and ammonia oxidation gene abundance. We further explored the mechanisms underlying the effects of intercropping on nitrate supply and N regulation. The results showed that both content and intensity of soil nitrate increased with N application rate. Under the same N level, nitrate content in intercropping soil was lower than that in monocropping soil. Nitrogen application increased soil nitrification potential, with stronger effects in monocropping than that of intercropping. The amoA gene abundance of AOB in soil was greater than that of AOA. The abundance of amoA gene for both AOA and AOB were increased firstly and then decreased with increasing N application rate when potato intercropped with maize. Under the same N application rate, AOA gene and AOB gene in all treatments (except N2) in intercropping were lower than those in the monocropping. The amoA gene abundance of soil AOB and AOA decreased and nitrification potential was weakened when potato intercropped with maize, resulting in a decrease of soil nitrate content and intensity. Therefore, intercropping led to a reduction of soil nitrate supply, which was related to the microbial process of soil N transformation. Much attention should be paid to soil N supply under the condition of potato and maize intercropping.

Species diversity can be overestimated by a fixed empirical threshold: insights from DNA barcoding of the genus Cletus (Hemiptera: Coreidae) and the meta-analysis of COI data from previous phylogeographical studies.

The use of genetic distances to identify species within the framework of DNA barcoding has to some extent improved the development of biodiversity studies. However, using a fixed empirical threshold to delimit species may lead to overestimating species diversity. In this study, we use a new data set of COI sequences for 366 specimens within the genus of Cletus as well as conduct an analysis on the same genetic data for collected morphologically defined species from previous phylogeographical studies, to test whether high intraspecific genetic divergences are common with the premises of comprehensive sampling. The results indicate C. graminis Hsiao & Cheng , is the same species with C. punctiger (Dallas, 1852) and should be synonymized and that the distributional record of C. pugnator (Fabricius, 1787) in China is correct. High intraspecific genetic differentiations (0%-4.35%) were found in C. punctiger. Furthermore, as to the mined data, the maximum intraspecific K2P distances of 186 species (48.44% of 384) exceed 3%, and 101 species (26.30%) can be divided into two or more clusters with a threshold of 3% in cluster analysis. If genetic distance is used to delimit species boundaries, the minimum interspecific K2P distance of the congeneric species should be considered rather than only using the fixed empirical value; otherwise, the species richness may be overestimated in some cases.

Evaluation of the effects of ketamine on spinal anesthesia with levobupivacaine or ropivacaine.

Spinal anesthesia or regional anesthesia is a potent anesthetic procedure. Additional modalities have been sought to increase the duration of block in spinal anesthesia. Ketamine is an N-methyl-D-aspartate (NMDA) receptor blocker that has an anesthetic effect when injected intrathecally and has a synergic effect with bupivacaine. Ketamine also has potent analgesic properties. The present study investigated the effect of intrathecally administered ketamine on spinal anesthesia with levobupivacaine or ropivacaine. Sprague-Dawley rats at post-natal day 21 were exposed to spinal anesthesia with 0.5% levobupivacaine or 0.5% ropivacaine. Separate groups of rats were treated with intrathecal ketamine at a 5 or 10 mg/kg bodyweight dose along with ropivacaine or levobupivacaine. The thermal and mechanical withdrawal latencies of the animals were determined using hot plate and von Frey filaments, respectively. A rotarod apparatus was employed to assess the capacity of the rats to rotate the spindle at 24 h following anesthesia. The gait of the rat pups was also assessed. Intrathecal administration of ketamine resulted in dense blocks and extended the duration of spinal blocks as evidenced by thermal latencies and responses to von Frey filaments. The latency to fall was shorter in rats exposed to ketamine along with ropivacaine or levobupivacaine spinal anesthesia. The gait parameters were also more disturbed upon ketamine administration. In conclusion, ketamine administration with ropivacaine or levobupivacaine increased the intensity and duration of spinal blockade, thereby increasing the anesthetic effects.

Phylogenetic divergences of the true bugs (Insecta: Hemiptera: Heteroptera), with emphasis on the aquatic lineages: the last piece of the aquatic insect jigsaw originated in the Late Permian/Early Triassic.

Heteroptera are among the most diverse hemimetabolous insects. Seven infraorders have been recognized within this suborder of Hemiptera. Apart from the well-established sister-group relationship between Cimicomorpha and Pentatomomorpha (= Terheteroptera), the two terminal lineages, the relationships among the other five infraorders are still controversial, of which three (Gerromorpha, Nepomorpha and Leptopodomorpha) are intimately connected to aquatic environments. However, the various and often conflicting available phylogeny hypotheses do not offer a clear background for a connection between diversification and palaeoenvironments. In this study, a molecular data set representing 79 taxa and 10 149 homologous sites is used to infer the phylogenetic relationships within Heteroptera. Bayesian inference, maximum-likelihood and maximum parsimony analyses were employed. The results of phylogenetic inferences largely confirm the widely accepted phylogenetic context. Estimation of the divergence time based on the phylogenetic results revealed that Gerromorpha, Nepomorpha and Leptopodomorpha originated successively during the period from the Late Permian to Early Triassic (269-246 Ma). This timescale is consistent with the origin and radiation time of various aquatic holometabolans. Our results indicate that the aquatic and semi-aquatic true bugs evolved under environmental conditions of high air temperature and humidity in an evolutionary scenario similar to that of the aquatic holometabolans.