Double benefits of mechanical wounding in enhancing chilling tolerance and lodging resistance in wheat plants

Chilling and lodging are major threats to wheat production. However, strategies that can be used to effectively mitigate the adverse effects of these threats are still far from clear. Mechanical wounding is a traditional agronomic measure, whereas information about the role it plays in wheat chilling and lodging is scant. The aim of the present study was to investigate mechanisms underlying the protective roles of mechanical wounding in alleviating damage from chilling at jointing stage and enhancing lodging resistance after anthesis of winter wheat (Triticum aestivum L.). Our data show that net photosynthesis rate, maximum photochemical efficiency of photosystem II, activity of the antioxidant enzymes and osmolytes were significantly increased in the latest fully expanded leaves of wounded plants under chilling. Wounding also reduced hydrogen peroxide accumulation, electrolyte leakage and water loss in wounded plants. Moreover, mechanical wounding significantly reduced the length but increased the diameter and wall thickness of the basal second internode of the main stem. Quantitative and histochemical analysis further indicated that wounding increased lignin accumulation and activity of enzymes involved in lignin synthesis, which resulted in increased mechanical strength and the lodging resistance index in the main stem. We conclude from our data that mechanical wounding confers both cold tolerance by alleviating the damage caused by chilling at jointing stage and lodging resistance after anthesis of wheat plants.

Uniform-Sized Indium Quantum Dots Grown on the Surface of an InGaN Epitaxial Layer by a Two-Step Cooling Process

A new method to grow Indium quantum dots (In QDs) on the surface of an epitaxial InGaN layer by MOCVD is proposed. Uniform-sized In quantum dots have been found to form on the surface of an InGaN layer when a two-step cooling process is taken. Through analyzing, we found that the formation of In QDs on the surface is due to the reaction between the surface In-rich layer and the carrier gas H₂ at the lower temperature period in the two-step cooling process. At the same time, as the density of In QDs is closely dependent on the surface In-rich layer, this provides us a way to study the surface property of the InGaN layer directly.

Heat stress negatively affects the transcriptome related to overall metabolism and milk protein synthesis in mammary tissue of midlactating dairy cows

Inadequate dry matter intake only partially accounts for the decrease in milk protein synthesis during heat stress (HS) in dairy cows. Our hypothesis is that reduced milk protein synthesis during HS in dairy cows is also caused by biological changes within the mammary gland. The objective of this study was to assess the hypothesis via RNA-Seq analysis of mammary tissue. Herein, four dairy cows were used in a crossover design where HS was induced for 9 days in environmental chambers. There was a 30-day washout between periods. Mammary tissue was collected via biopsy at the end of each environmental period (HS or pair-fed and thermal neutral) for transcriptomic analysis. RNA-Seq analysis revealed HS affected >2,777 genes (false discovery rate-adjusted P value < 0.05) in mammary tissue. Expression of main milk protein-encoding genes and several key genes related to regulation of protein synthesis and amino acid and glucose transport were downregulated by HS. Bioinformatics analysis revealed an overall decrease of mammary tissue metabolic activity by HS (especially carbohydrate and lipid metabolism) and an increase in immune activation and inflammation. Network analysis revealed a major role of TNF, IFNG, S100A8, S100A9, and IGF-1 in inducing/controlling the inflammatory response, with a central role of NF-κB in the process of immunoactivation. The same analysis indicated an overall inhibition of PPARγ. Collectively, these data suggest HS directly controls milk protein synthesis via reducing the transcription of metabolic-related genes and increasing inflammation-related genes.

[Mid-to-long term outcomes and influence factors of postoperative concurrent chronic ankle instability and posterior ankle impingement]

OBJECTIVE

To investigate the mid-to-long-term efficacy of patients with chronic ankle instability combined with posterior impingement syndrome after 3-9 years of follow-up, and to analyze the influencing factors.

METHODS

From February 2010 to December 2015, 46 patients underwent concurrent lateral ankle ligament repair with posterior ankle arthroscopic surgery at the Institute of Sports Medicine, Peking University Third Hospital. The patient was first placed in a prone position and underwent arthroscopic debridement for the posterior impingement. After finishing the posterior arthroscopy, the surgeon and assistants first translated the patient to the affected side, then turned to the healthy side, and changed the position to the supine position. During the turning over, another assistant held the arthroscope and the instrument to ensure that it was sterile and could be used without replacement. The anterior ankle arthroscopy was operated if necessary and the lateral ankle ligament repair was anatomic repaired with anchors. The 42 patients were followed up, including 26 males and 16 females. The average age was (28.9±10.0) years. The patient's clinical symptoms, joint stability, mobility and motor function were compared by questionnaire and physical examination. The preoperative and postoperative visual analogue scale (VAS) scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, Tegner scores were compared, and the clinical scores and the patient age, gender, height and weight were compared. The correlations between body mass index (BMI), preoperative duration, surgery duration, and cartilage injury were analyzed.

RESULTS

The mean follow-up time was (71.8±22.8) months. The postoperative VAS scores (1.0 vs. 5.0, P<0.001), AOFAS scores (92 vs. 80, P<0.001), and Tegner scores (6.5 vs. 2, P<0.001) were significantly superior to the preoperative levels. The excellent and good rate was 97.6%. The postoperative VAS score (t=2.719, P=0.10), AOFAS score (t=-2.853, P=0.10), Tegner score (t=-3.443, P=0.001) and time to return exercise (t=2.814, P=0.008) were negatively correlated with the patient age, and the postoperative VAS score was negatively correlated with cartilage injury (Z=-2.195, P=0.028).

CONCLUSION

The mid-to-long-term clinical outcomes of the chronic ankle ligament instability combined with the posterior impingement were good. The age of the patients was negatively correlated with the clinical outcome. The combined cartilage injury could aggravate the postoperative pain.

[Retrospective analysis of modified Karlsson surgery for chronic calcaneofibular ligament injury]

Objective: To retrospectively evaluate the therapeutic effect and influencing factors of the modified Karlsson operation (anchor method) in treating chronic rupture of the calcaneofibular ligament (CFL). Methods: From August 2010 to May 2014, the data of 24 patients with calcaneofibular ligament rupture treated in Institute of Sports Medicine, Third Hospital of Peking University were retrospectively analyzed. All cases were repaired with modified Karlsson operation (anchor method). There were 14 males and 10 females, with an average age of (30±9) years, and the average body mass index (BMI) was (25±5) kg/m(2). Visual analogue pain score (VAS), American Foot and Ankle Surgery Association score (AOFAS), Tegner knee motion score, ankle stability and mobility were followed up and analyzed. The paired t test was used to compare the normal distribution data before and after the operation. Results: The average follow-up time was (41±13) months. Compared with pre-operation, VAS score decreased significantly at the last follow-up [0(0,7) vs 5(0,8), Z=4.13,P=0.000], AOFAS score increased significantly (94±10 vs 70±14, t=8.94, P<0.05), Tegner score increased significantly (4.7±1.5 vs 2.8±1.3, t=6.87, P<0.05), all improved significantly. AOFAS score was excellent in 19 cases, good in 4 cases and moderate in 1 case, the excellent and good rate was 95.8%. Among them, 20 cases (83.3%) were satisfied with the recovery effect after the operation. Postoperative sprain occurred in 5 cases (20.8%) and ankle mobility was limited in 3 cases (12.5%). Conclusions: The modified Karlsson operation (anchor method) can restore the stability of the ankle joint by treating the chronic rupture of CFL. It is an effective therapy for lateral ankle instability.

Carrier Redistribution Between Two Kinds of Localized States in the InGaN/GaN Quantum Wells Studied by Photoluminescence

The InGaN/GaN multi-quantum wells (MQWs) are prepared at the same condition by metal-organic chemical vapor deposition (MOCVD) except the thickness of cap layers additionally grown on each InGaN well layer. The photoluminescence (PL) intensity of the thin cap layer sample is much stronger than that of thicker cap layer sample. Interestingly, the thick cap layer sample has two photoluminescence peaks under high excitation power, and the PL peak energy-temperature curves show an anomalous transition from reversed V-shaped to regular S-shaped with increasing excitation power. Meanwhile, it exhibits a poorer thermal stability of thick cap layer sample under higher excitation power than that under lower excitation power. Such an untypical phenomenon is attributed to carrier redistribution between the two kinds of localized states which is induced by the inhomogeneous distribution of indium composition in thick cap layer sample. Furthermore, the luminescence of deep localized states has a better thermal stability, and the luminescence of shallow localized states has a poor thermal stability. In fact, such a severer inhomogeneous indium distribution may be caused by the degradation of subsequent epitaxial growth of InGaN/GaN MQWs region due to longer low-temperature GaN cap layer growth time.

[Reconstruction of neglected Achilles tendon rupture: flexor hallucis longus transfer versus gastrocnemius turn-down flaps]

Objective: To compare the outcome of either flexor hallucis longus transfer or turn-down of proximal Achilles tendon tissue repair in treating chronic Achilles tendon rupture. Methods: The clinical data of 21 patients who underwent repair of Myerson type Ⅲ chronic Achilles tendon rupture at Peking University Sports Medicine Research Institute from May 2012 to March 2015 were retrospectively analyzed. Among them, 11 cases were treated with flexor hallucis longus (FHL) transfer, and 10 cases were treated with gastrocnemius turn-down flaps repair. The American Orthopedic Foot & Ankle Society (AOFOS) hindfoot score and Tegner motor function score before and after surgery were recorded and compared between the two groups. Data comparison between groups was performed with t test. Results: The patients in the both group were followed up for an average of (21±7) months. The postoperative AOFOS hindfoot score in the long flexor and gastrocnemius groups were both significantly higher than those before surgery, and the differences were statistically significant (97.7±2.6 vs 72.0±8.1 and 96.0±5.5 vs 78.5±6.4, t=10.70, 6.42, both P<0.05).The postoperative Tegner scores of the two groups were also significantly higher than those before surgery (4.2±1.4 vs 0.7±0.4 and 4.1±0.8 vs 0.6±0.5,t=7.29, 9.35, both P<0.05). There were no significant differences in postoperative AOFOS hindfoot scores and Tegner motor function scores between the two groups (both P>0.05). Conclusion: The flexor hallucis longus transfer and turn-down of proximal Achilles tendon tissue repair can both get satisfactory results in treating chronic Achilles tendon rupture.

Findings from aetiological investigation of Auditory Neuropathy Spectrum Disorder in children referred to cochlear implant programs

OBJECTIVES

Auditory neuropathy spectrum disorder (ANSD) is an audiological diagnosis characterised by hearing dysfunction in the presence of intact outer hair cell function in the cochlea. ANSD is thought to account for 7-10% of all childhood permanent hearing impairment, and can result from a range of pathological processes. This paper describes the rationale, methods and findings from the aetiological investigation of ANSD.

METHODS

Retrospective audit of four cochlear implant programmes.

RESULTS

97 patients were identified. 79% of patients were identified before the age of one. Prematurity and jaundice were the most frequently identified aetiological factors. 33 patients had cochlear nerve deficiency on imaging. Genetic diagnoses identified included otoferlin, SX010 gene, connexin 26 and A1FM1 gene mutations. ANSD was seen in conjunction with syndromes including Kallman syndrome, CHARGE syndrome, X-linked deafness, SOTOS syndrome, Brown Vieletto Van Laere syndrome, and CAPOS syndrome.

DISCUSSION

We present a two-level system of aetiological investigation that is clinically practical. Patients with ANSD sufficiently severe to consider cochlear implantation are generally identified at an early age. Aetiological investigation is important to guide prognosis and identify comorbidity.

CONCLUSION

Prematurity and jaundice are the most commonly identified aetiological factors in ANSD. Imaging findings identify crucial factors in a significant minority. An important minority may have genetic and syndromic diagnoses that require further management.

Role of Si and C Impurities in Yellow and Blue Luminescence of Unintentionally and Si-Doped GaN

Both yellow luminescence (YL) and blue luminescence (BL) bands of GaN films have been investigated for decades, but few works report the relationship between them. In this study, two sets of GaN samples grown via metalorganic chemical vapor deposition (MOCVD) were investigated. A close relationship was found between the YL and BL bands for unintentionally doped GaN and Si-doped GaN samples, both of which were grown without intentional acceptor doping. It was found that the intensity ratio of blue luminescence to yellow luminescence (I_BL/I_YL) decreases sharply with the increase in carbon impurity concentration, even though both I_BL and I_YL increase obviously. It was also found that I_BL/I_YL decreases sharply with the increase in Si doping concentration. It is suggested that the C and Si impurities play important role in linkage and competition of the blue and yellow luminescence.

A novel method for assessing proximal tibiofibular joint on MR images in patients with knee osteoarthritis

OBJECTIVES

To validate a method to measure the morphological parameters of the proximal tibiofibular joint (PTFJ) in patients with knee osteoarthritis (OA).

METHODS

408 participants were examined in this cross-sectional subject-based study. We calculated the fibular contacting area of PTFJ (S) and its projection areas onto the horizontal plane (load-bearing area, Sτ), the sagittal plane (lateral stress-bolstering area, Sφ) and the coronal plane (posterior stress-bolstering area, Sυ). Joint space narrowing (JSN) and osteophyte was measured using radiographs. Cartilage defects, bone marrow lesions (BMLs) and cartilage volume were evaluated using magnetic resonance imaging (MRI).

RESULTS

The average PTFJ fibular contacting area was 2.4 cm² (SD, ±0.7 cm²). Intra-observer and inter-observer reliabilities of measures of PTFJ morphological parameters were excellent (≥0.90). S, Sτ and Sφ were significantly associated with JSN in the medial tibiofemoral compartment (PR: 1.40, 95% CI 1.10-1.78; PR: 1.65, 95% CI 1.25-2.18 and PR: 0.53, 95% CI 0.29-0.97, respectively). There was a significantly positive association between S, Sτ and medial and/or femoral tibial cartilage defects. S, Sτ and Sυ were significantly and positively associated with medial and/or femoral tibial BMLs (PR: 1.36, 95% CI 1.12-1.64; PR: 1.47, 95% CI 1.17-1.83; and PR: 1.39, 95% CI 1.06-1.82, respectively) after adjustment. S and Sτ were significantly and negatively associated with medial tibial cartilage volume.

CONCLUSIONS

This novel method to assess the morphological parameters of PTFJ in MRI is reproducible. These parameters are associated with knee radiographic and MRI-based OA-related structural abnormalities, suggesting clinical construct validity. Its predictive validity needs to be examined in future longitudinal studies.