This Review is a personal reflection on the research that led to the development of a method for growing gallium nitride (GaN) on a sapphire substrate. The results paved the way for the development ...of smart display systems using blue LEDs. The most important work was done in the mid to late 80s. The background to the author’s work and the process by which the technology that enables the growth of GaN and the realization of p‐type GaN was established are reviewed.
Growing success: The invention of a method to grow gallium nitride (GaN) on sapphire substrate formed the basis for the development of flat screens and smart displays based on blue‐light‐emitting diodes. Hiroshi Amano gives a personal account of the background of the studies that led to the technologies for growing GaN and producing p‐GaN.
This article combines two papers, “Nobel Lecture: Growth of GaN on sapphire via low-temperature deposited buffer layer and realization of p-type GaN by Mg doping followed by low-energy electron beam ...irradiation,” Rev. Mod. Phys., 87 (2015) 1133, and “MOCVD of nitrides,” Handbook of Crystal Growth Second Edition, Volume III, Part A, Chapter 16, Elsevier, 683–704, 2015. For more detailed information, please read the two original papers.
This is a personal history of one of the Japanese researchers engaged in developing a method for growing GaN on a sapphire substrate, paving the way for the realization of smart television and ...display systems using blue LEDs. The most important work was done in the mid to late 1980s. The background to the author's work and the process by which the technology enabling the growth of GaN and the realization of p‐type GaN was established are reviewed.***
This is a personal history of Hiroshi Amano as one of the Japanese researchers engaged in developing a method for growing GaN on a sapphire substrate, paving the way for the realization of smart television and display systems using blue LEDs. The most important work was done in the mid to late 1980s. The background to the author's work and the process by which the technology enabling the growth of GaN and the realization of p‐type GaN was established are reviewed.
Background:
Many factors are involved in causing patellar instability or recurrent patellar dislocations. However, factors affecting the outcomes of anatomic medial patellofemoral ligament (MPFL) ...reconstruction have not been fully documented.
Purpose:
To evaluate the rate of recurrent patellar instability after isolated MPFL reconstruction and to elucidate factors affecting the outcomes of isolated MPFL reconstruction using multivariable statistics.
Study Design:
Case-control study; Level of evidence, 3.
Methods:
A total of 42 patients (44 knees) who underwent isolated, anatomic MPFL reconstruction using a semitendinosus autograft without any additional patellar stabilization procedures for treating recurrent patellar dislocations were included in this study. All patients were followed for more than 2 years; the mean follow-up period was 3.2 years (range, 2-9 years). Postoperative patellofemoral instability was diagnosed when the patient complained of recurrent patellar subluxations or dislocations or had a positive apprehension sign during follow-up. Preoperative radiographic findings were obtained using plain radiography and computed tomography. Femoral tunnel positions were assessed on postoperative radiographs. The strength of the relationship between postoperative patellofemoral instability and potential risk factors such as preoperative age, sex, body mass index, patellar type, sulcus angle, congruence angle, lateral tilt angle, patellar height, tibial tubercle–trochlear groove (TT-TG) distance, degree of trochlear dysplasia, and femoral bone tunnel position were evaluated by univariate and multivariate logistic regression analyses.
Results:
At follow-up, 2 knees had experienced a redislocation (4.5%). A positive apprehension sign was still evident in 8 knees (18.2%). Three factors, including the sulcus angle, the congruence angle, and trochlear dysplasia, were extracted by single linear regression analysis. Univariate logistic regression analysis showed that the sulcus angle (odds ratio OR, 1.11; 95% CI, 1.01-1.22; P = .04) and trochlear dysplasia (OR, 3.04; 95% CI, 1.39-6.63; P = .01) were associated with postoperative patellofemoral instability. Trochlear dysplasia was independently associated with postoperative patellofemoral instability by multivariable logistic regression analysis (P < .05). An increased TT-TG distance exerted a significant effect on the outcomes of MPFL reconstruction, particularly in patients with type D trochlea.
Conclusion:
Severe trochlear dysplasia is the most important predictor of residual patellofemoral instability after isolated MPFL reconstruction. In addition, an increased TT-TG distance affected the outcomes in patients with type D trochlea. Additional patellar stabilization procedures should be considered for patients with severe trochlear dysplasia and an increased TT-TG distance.
A non-filter virus inactivation unit was developed that can control the irradiation dose of aerosolized viruses by controlling the lighting pattern of a 280 nm deep-UV (DUV)-LED and the air flowrate. ...In this study, the inactivation properties of aerosolized SARS-CoV-2 were quantitatively evaluated by controlling the irradiation dose to the virus inside the inactivation unit. The RNA concentration of SARS-CoV-2 remained constant when the total irradiation dose of DUV irradiation to the virus exceeded 16.5 mJ/cm2. This observation suggests that RNA damage may occur in regions below the detection threshold of RT-qPCR assay. However, when the total irradiation dose was less than 16.5 mJ/cm2, the RNA concentration monotonically increased with a decreasing LED irradiation dose. However, the nucleocapsid protein concentration of SARS-CoV-2 was not predominantly dependent on the LED irradiation dose. The plaque assay showed that 99.16% of the virus was inactivated at 8.1 mJ/cm2 of irradiation, and no virus was detected at 12.2 mJ/cm2 of irradiation, resulting in a 99.89% virus inactivation rate. Thus, an irradiation dose of 23% of the maximal irradiation capacity of the virus inactivation unit can activate more than 99% of SARS-CoV-2. These findings are expected to enhance versatility in various applications. The downsizing achieved in our study renders the technology apt for installation in narrow spaces, while the enhanced flowrates establish its viability for implementation in larger facilities.
Purpose
This study aimed to identify independent predictive factors for return to sports (RTS) after anterior cruciate ligament (ACL) reconstruction in competitive-level athletes and to determine ...optimal cut-off values for these factors at 6 months after surgery.
Methods
A total of 124 competitive athletes (50 males and 74 females; mean age, 17.0 years; preinjury Tegner activity scale > 7) who underwent primary ACL reconstruction were enrolled. Assessments at 6 months after surgery consisted of knee functional tests quadriceps index, hamstrings index, and single-leg hop for distance (SLH) and 2 self-report questionnaires IKDC subjective score and ACL-Return to Sport after Injury scale (ACL-RSI). At 1 year after surgery, athletes were classified into the RTS group (
n
= 101) or non-RTS group (
n
= 23) based on self-reported sports activities. After screening possible predictive factors of RTS, multivariate logistic regression and receiver operating characteristic curve analyses were performed to identify independent factors.
Results
Multivariate logistic regression analysis identified SLH (odds ratio, 2.861 per 10 unit increase;
P
< 0.001) and ACL-RSI (odds ratio, 1.810 per 10 unit increase;
P
= 0.001) at 6 months as independent predictors of RTS at 1 year after surgery. Optimal cut-off values of SLH and ACL-RSI were 81.3% (sensitivity = 0.891; specificity = 0.609) and 55 points (sensitivity = 0.693; specificity = 0.826), respectively.
Conclusion
In competitive athletes, SLH < 81% and ACL-RSI < 55 points at 6 months after surgery were associated with a greater risk of unsuccessful RTS at 1 year after surgery. SLH and ACL-RSI at 6 months could serve as screening tools to identify athletes who have difficulties with returning to sports after ACL reconstruction.
Level of evidence
III.
Purpose The purpose of this study was to histologically identify the direct and indirect insertion of the femoral anterior cruciate ligament (ACL) insertion. Furthermore, we quantitatively measured ...the direct femoral insertion area by use of the 3-dimensional (3D) volume-rendered (VR) computed tomography (CT) model. Methods By use of 8 intact cadaveric knees, the lateral femoral condyle including the ACL attachment was sectioned for histologic examination in 3 oblique-axial planes parallel to the roof of the intercondylar notch and in the sagittal planes. Before sectioning, these knees had been subjected to CT to obtain 3D VR images of the femur. Once the direct insertion of the ACL was identified on each histologic section, the corresponding image was superimposed on the corresponding CT image. Results The direct ACL insertion, in which dense collagen fibers were connected to the bone by the fibrocartilaginous layer, was microscopically identified at the region between the posteromedial articular cartilage margin of the lateral femoral condyle and the linear bony ridge 7 to 10 mm anterior to the articular cartilage margin. Meticulous comparison of histologic analysis and the 3D VR CT model showed that the ACL direct insertion coincided with a crescent-shaped hollow just behind the linear bony ridge. The direct insertion measured 17.4 ± 0.9 mm (mean ± SD) in length, 8.0 ± 0.5 mm in width, and 128.3 ± 10.5 mm2 in area. Conclusions The direct insertion of the ACL is located in the depression between the resident's ridge and the articular cartilage margin on the lateral femoral condyle. It measured 17.4 ± 0.9 mm in length, 8.0 ± 0.5 mm in width, and 128.3 ± 10.5 mm2 in area. Clinical Relevance Delineation of the ACL femoral direct insertion by 3D VR CT could be a useful tool for planning of accurate femoral tunnel positioning in anatomic ACL reconstruction.
•We present an overview of the effect of environmental stressors on phytoseiid mites.•We discuss the strategies used by phytoseiid mites to avoid or tolerate environmental stress.•The factors that ...either promote or depress stress tolerance in phytoseiid mites are emphasized.
Predatory mites of the family Phytoseiidae are important natural enemies of phytophagous mites and small insects. Phytoseiid mites often experience a variety of stresses brought about by changing or fluctuating environmental factors in the field or laboratory or during their commercial production. These factors include abiotic stressors such as extreme temperature and humidity, ultraviolet radiation, and pesticides, and biotic stressors such as cannibalism, intraguild predation, food shortage, and pathogens, all of which affect the biocontrol potential of phytoseiid mites. The extent to which an environmental stressor may affect the biocontrol efficacy of phytoseiid mites depends on the characteristics of the species and on other concurrent stresses. In this review, we discuss the effects of environmental stressors on various biological and ecological aspects of phytoseiid mites, such as development, survival, reproduction, and predation, and the mites’ adaptation strategies to these stressors.
