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There is no clear consensus on the safety of renin-angiotensin-aldosterone system inhibitors in patients with contrast media exposure. We aimed to assess the safety of renin-angiotensin-aldosterone system inhibitors in patients exposed to contrast media at 1-year follow-up. Patients treated with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) were recruited and randomly divided into 2 groups (1:1 ratio): with ACEI/ARB group (ACEI/ARB continued throughout the study period) and without ACEI/ARB group (ACEI/ARB stopped 24 hours before and continued 48 hours after the procedure). The primary endpoint was contrast-induced acute kidney injury (CI-AKI) and secondary endpoints were major adverse cardiovascular events (MACEs), and the need for renal replacement therapy during hospitalization and at 1-year follow-up. The occurrence rates of CI-AKI were not comparable in the ACEI/ARB group and the without ACEI/ARB group (2.92% and 2.62%, respectively; P = 0.866). No significant between-group differences were found with respect to the frequency of MACEs or renal replacement therapy during hospitalization and at 1-year follow-up. On subgroup analysis, among patients with estimated glomerular filtration rate (eGFR)lt; 45 mL/min, the incidence of CI-AKI was significantly higher in the ACEI/ARB group [17.95% (14/78) vs. 6.02% (5/83), P = 0.029]. Among patients with eGFR ≥ 45 mL/min, the incidence of CI-AKI was comparable in the 2 groups [0.87% (5/572) vs. 2.12% (12/567), P = 0.094]. The incidence of MACEs and renal replacement therapy was not comparable in the 2 groups, during hospitalization and at 1-year follow-up. ACEI or ARB treatment can safely be continued after exposure to contrast media, but not in patients with eGFRlt; 45 mL/min.

Background Sepsis is a serious disease and patients have high risk of short-term mortality. Despite extensive research, there are no simple and reliable tools for predicting outcomes. Purpose To assess the value of the combined use of high-density lipoprotein 2b (HDL2b) level and Sequential Organ Failure Assessment (SOFA) score in predicting short-term mortality from sepsis. Materials and Methods Forty-seven sepsis patients and 11 non-septic controls who were admitted to an intensive care unit (ICU) from January 2020 to December 2021 were examined. HDL2b as a percentage of total HDL-C and SOFA score were recorded on the first day after admission. The primary endpoint was 28-day mortality and the secondary outcome was total in-hospital mortality. Results Compared to non-septic controls, septic patients had a lower HDL2b level (10.95% [8.95, 12.96] vs. 23.78% [14.53, 29.16], p vs. 11.78 [7.20, 13.40], p = 0.002]. The areas under the receiver operating characteristic curves for predicting 28-day mortality were 0.755 for HDL2b, 0.782 for SOFA, and 0.806 for HDL2b + SOFA. Multivariate analyses indicated that HDL2b (adjusted odds ratio [aOR]: 0.780 [0.621, 0.978]), SOFA (aOR: 1.299 [0.927, 1.820]), and HDL2b + SOFA (aOR: 8.958 (1.037, 85.199]) were significant predictors of 28-day mortality. Patients with higher HDL2b + SOFA scores had higher rates of 28-day and overall in-hospital mortality. Conclusions Sepsis patients have reduced levels of HDL2b. HDL2b + SOFA score was a reliable predictor of 28-day and overall in-hospital mortality in sepsis patients.

Intravenous morphine is a controversial treatment for acute heart failure (AHF). This study aimed to evaluate and compare the efficacy of intravenous morphine treatment vs. no morphine treatment in AHF patients. Relevant research conducted before June 2020 was retrieved from electronic databases. One unpublished study of our own was also included. Studies were eligible for inclusion if they compared AHF patients treated with intravenous morphine and patients who did not receive morphine. This meta-analysis included three propensity-matched cohorts and two retrospective analyses, involving a total of 149,967 patients (intravenous-morphine group, n = 22,072; no-morphine group, n = 127,895). There was a non-significant increase in the in-hospital mortality in the morphine group (combined odds ratio [OR] = 2.14, 95% confidence interval [CI]: 0.88–5.23, p = 0.095, I2 = 97.1%). However, subgroup analyse showed that the rate of in-hospital mortality with odds of 1.41 times more likely (95% CI: 1.11–1.80, p = 0.005, I2 = 0%) in those receiving vs. not receiving intravenous morphine. No significant correlation was found between intravenous morphine and invasive mechanical ventilation (OR = 2.19, 95% CI: 0.84–5.73, p = 0.10, I2 = 94.2%; subgroup analysis: OR = 2.24, 95% CI: 0.70–7.21, p = 0.176, I2 = 95.1%) or long-term mortality (hazard ratio = 1.15, 95% CI: 0.96–1.34, p = 0.335; I2 = 8.6%). The administration of intravenous morphine to patients with AHF may be related to in-hospital mortality, but not to invasive mechanical ventilation and long-term mortality.

BackgroundInfection during hospitalization is a serious complication among patients who suffered from acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI); however, there are no suitable and accurate means to assess risk. This study aimed to develop and validate a simple scoring system to predict post-AMI infection in such patients.MethodsAll patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI consecutively enrolled from January 2010 to May 2016 were served as derivation cohort, and those from June 2016 to May 2018 as validation cohort, respectively. The primary endpoint was post-AMI infection during hospitalization, and all-cause death and major adverse cardiovascular events (MACE) were considered as secondary endpoints. The simplified risk model was established using logistic regression. The area under the receiver operating curve and calibration of predicted and observed infection risk were calculated.ResultsA 24-point risk score was developed, with infection risk ranging from 0.7 to 99.6% for patients with the lowest and highest score. Seven variables including age, Killip classification, insulin use, white blood cell count, serum albumin, diuretic use, and transfemoral approach were included. This model achieved the same high discrimination in the development and validation cohort (C-statistic:0.851) and revealed adequate calibration in both datasets. The incidences of post-AMI infection increased steadily across risk score groups in both development (1.3, 5.1, 26.3, and 69.1%; P < 0.001) and validation (1.8, 5.9, 27.2, and 79.2%; P < 0.001) cohort. Moreover, the risk score demonstrated good performance for infection, in-hospital all-cause death, and MACE among these patients, as well as in patients with the non-ST-elevation acute coronary syndrome.ConclusionThis present risk score established a simple bedside tool to estimate the risk of developing infection and other in-hospital outcomes in patients with STEMI undergoing PCI. Clinicians can use this risk score to evaluate the infection risk and subsequently make evidence-based decisions.

Atherosclerosis is a systemic disease affecting the whole arterial tree of the human body, and it is the leading cause of cardiovascular diseases.Vascular smooth muscle cells (VSMCs) have been identified to play a key role in the development of atherosclerosis. MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs, and they play a critical role in many biological processes including regulating cell proliferation, migration and apoptosis. However, till now, the expression and role of miR-133b in atherosclerosis remain largely unknown. Therefore, our purpose was to investigate the expression and role of miR-133b in atherosclerosis and to explore the underlying mechanism. The results showed that miR-133b was down-regulated in the blood and vascular plaque tissues of rabbits with atherosclerosis. Matrix metallopeptidase 9 (MMP-9) was a direct target of miR-133b. In addition, our data indicated that miR-133b mimic could significantly inhibit rVSMC cell proliferation activity, migration ability and induce cell apoptosis compared with the control group, and all these effects were reversed by MMP-9-plasmid. Taken together, these findings highlight an important role for miR-133b/MMP-9 axis in atherosclerosis. And miR-133b might be a valuable clinical marker and therapeutic target for atherosclerosis.

Background: Currently, there is no validated multivariate model to predict probability of coronary artery spasm (CAS) in patients with acute chest pain. Methods: A total of 976 consecutive patients with acute chest pain were enrolled. Patients were divided into two groups based on the presence of significant CAS. To adjust potential confounders, a multivariable analysis was performed and a clinical diagnostic score system for CAS was utilized for score derivation. Results: Multivariable analysis model selected 6 predictors for CAS. The integer score was assigned to each predictors: angina at rest alone (10 points), positive of hyperventilation test (8 points), allergies (3 points), asthma, ST-segment elevation and myocardial bridge (2 points each). We showed that the clinical diagnostic score system had accuracy in predicting CAS, as measured by the area under the curve (AUC), which was 0.952–0.966. The cut-off baseline value for the clinical diagnostic score system was set to 11–12 points with specificity of 91.0–93.3% and sensitivity of 90.7–92.9%, respectively. Conclusion: A clinical diagnostic score system was derived and validated as an accurate tool for estimating the pretest probability of CAS in patients with acute chest pain. Keywords: Acute chest pain, Coronary artery spasm, Clinical diagnostic score system

Background: An accurate biomarker at hospital discharge is needed to identify patients with acute infective endocarditis (IE) who are at high risk of mortality. This prospective observational study evaluated the prognostic value of C-reactive protein (CRP).Methods: Patients with acute IE (n = 343) and hospitalized at 2 university-affiliated medical centers from January 2014 to December 2019 were enrolled. Patients were categorized as having low or high CRP (n = 217 and 126, respectively) at hospital discharge according to the optimal cutoff (CRP = 6.5 mg/L) determined via receiver-operating characteristic curve analysis. The primary endpoint was all-cause death, from hospital discharge to 1 year. The secondary endpoint was the cumulative rate of rehospitalization or paravalvular abscess at 1 year.Results: At the 12-month follow-up, the mortality rate of the high-CRP group (21.43%) was significantly higher than that of the low-CRP group (2.76%, log-rank P < 0.0001). The multivariate regression analysis indicated that the high-CRP group had a higher excess mortality hazard risk (HR = 4.182; 95% CI: 2.120, 5.211; P < 0.001). The cumulative 1-year incidence of paravalvular abscess of the high-CRP group (11.90%) was significantly higher than that of the low-CRP (5.07%; P = 0.022). The cumulative rate of heart rehospitalizations of the 2 groups were similar (18.25% cf. 14.29%, P = 0.273).Conclusion: For hospitalized patients with acute IE, a high CRP at discharge suggests a poor prognosis for 1-year mortality and paravalvular abscess.

ObjectivesThe use of aspirin to prevent cardiovascular disease in vasospastic angina (VSA) patients without significant stenosis has yet to be investigated. This study aimed to investigate the efficacy of aspirin use among VSA patients.DesignSystematic review and meta-analysis.Data sourcesPubMed, Web of Science and Cochrane Central Register of Controlled Trials were searched for relevant information prior to October 2020.Eligibility criteria for selecting studiesAspirin use versus no aspirin use (placebo or no treatment) among VSA patients without significant stenosis.Data extraction and synthesisTwo investigators extracted the study data. ORs and 95% CIs were calculated and graphed as forest plots. The Newcastle-Ottawa Quality Assessment Scale tool and Begg’s funnel plot were used to assess risk of bias.ResultsFour propensity-matched cohorts, one retrospective analysis and one prospective multicentre cohort, in total comprising 3661 patients (aspirin use group, n=1695; no aspirin use group, n=1966) were included in this meta-analysis. Aspirin use and the incidence of major cardiovascular adverse events with follow-up of 1–5 years were not significantly correlated (combined OR=0.90, 95% CI: 0.55 to 1.68, p=0.829, I2=82.2%; subgroup analysis: OR=1.09, 95% CI: 0.81 to 1.47, I2=0%). No significant difference was found between aspirin use and the incidence of myocardial infarction (OR=0.62, 95% CI: 0.09 to 4.36, p=0.615, I2=73.8%) or cardiac death (OR=1.73, 95% CI: 0.61 to 4.94, p=0.444, I2=0%) during follow-up.ConclusionAspirin use may not reduce the risk of future cardiovascular events in VSA patients without significant stenosis.PROSPERO registration numberCRD42020214891.

Additional file 15: Table S10. The detailed information (version, website links, etc.) of genome assemblies of 14 other primates used in this study.

Additional file 9: Table S4. Statistics for Illumina reads mapped to the T. leucocephalus genome.

Additional file 22: Table S17. The expression of all genes in mineral absorption pathways from seven tissues of T. leucocephalus.

Additional file 6: Table S1. Illumina libraries used in the de novo sequencing of the T. leucocephalus genome.

Additional file 7: Table S2. Survey statistics for the T. leucocephalus genome.

Additional file 8: Table S3. T. leucocephalus genome assembly statistics.

Purpose To compare the clinical outcomes after thoracic endovascular aortic repair (TEVAR) with a bare stent to those after TEVAR alone in patients with complicated acute type B aortic dissection (cATBAD). Materials and Methods A prospective, randomized trial was conducted at 2 medical centers in China between 2010 and 2013. Patients with cATBAD were randomly assigned to receive TEVAR with a bare stent (n=42) or TEVAR only (n=42). Patients were scheduled to undergo computed tomography angiography at 3, 6, and 12 months and then annually to 5 years. The primary endpoint was all-cause mortality at 5 years; secondary outcomes were a composite of complications (endoleak, stent-graft–induced new entry, aortic rupture, and secondary intervention) and aortic remodeling at 1 and 5 years. Results All-cause death occurred in 1 (2.4%) patient in the TEVAR with bare stent group (lung cancer) and 5 patients (11.9%) in the TEVAR group (4 aorta-related) during the 5-year follow-up (log-rank p=0.025). The 1- and 5-year rates of complications and secondary interventions did not differ between the groups. Patients in the TEVAR with bare stent group had higher increases in the thoracic true lumen diameter (19.7±3.6 vs 17.0±6.2 mm, p=0.018) and abdominal true lumen diameter (13.7±4.8 vs 7.2±6.1 mm, pConclusion The addition of a distal bare stent to a thoracic stent-graft during TEVAR was associated with significantly improved long-term survival in cATBAD patients vs TEVAR only, likely due to the prevention of true lumen collapse and improvement of complete false lumen thrombosis of the dissected aorta.

Background: The available data regarding the safety of morphine use in cases of STEMI with AHF (Killip ≥2) remain insufficient. The aim of the study was to further examine the safety of intravenous morphine in patients with STEMI and AHF over 1 year of follow-up after primary percutaneous coronary intervention (PPCI).Methods: 275 consecutive patients with STEMI and AHF were included and divided into groups that did or did not receive in-hospital intravenous morphine. Endpoints included major adverse cardiovascular events (MACEs) and the need for invasive mechanical ventilation during hospitalization and 1 year of follow-up. Results: The in-hospital occurrences of cardiac death and cardiogenic shock were much higher in patients who received morphine than that those who did not (15.20% vs 6.67%, p=0.035; odds ratio [OR]=2.509, 95% confidence interval [CI] 1.121–5.620, and 14.40% vs 6.00%, p=0.033; OR=2.636, 95% CI 1.139-6.097, respectively). Additionally, more patients in the group treated with morphine experienced the secondary outcome of in-hospital invasive mechanical ventilation compared with the group not treated with morphine (19.20% vs 10.67%, p=0.031; OR=2.308, 95% CI 1.138–4.684). However, no difference between-group differences were observed for the incidence of MACEs, cardiac death, or all-cause death over 1 year of follow-up.Conclusions: Intravenous morphine administration is highly correlated with in-hospital MACEs and the need for additional invasive mechanical ventilation in STEMI patients with AHF after PPCI, but not for long-time adverse outcomes.

There is no clear consensus on the potential efficacy and indications for sympathectomy to prevent recurrence of vasospasm in patients with refractory coronary artery spasm (CAS).To compare the clinical outcomes of sympathectomy with those of conventional treatment in patients with refractory CAS.Patients with refractory CAS were randomly assigned to sympathectomy group (n = 37) or conventional treatment group (n = 42). The primary end point was a composite of major adverse cardiac event (MACE) episodes (including cardiac death, nonfatal myocardial infarction, unstable angina, heart failure, and life-threatening arrhythmia), and the secondary end point was death from any cause within 24 months after randomization.During the follow-up period of 24 months, the incidence of MACE in the sympathectomy and conventional treatment groups was 16.22 and 61.90%, respectively (P = 0.0001). All-cause death as the secondary end point occurred in zero and six (14.29%) patients, respectively (P = 0.0272). The Kaplan-Meier curve for MACE and all-cause death showed a significant between-group difference (log-rank test, P = 0.0013 and 0.0176, respectively).Compared with conventional treatment, sympathectomy significantly reduced the composite end point of MACE episodes and death from any cause in patients with refractory CAS by effectively preventing recurrence of vasospasm.

Cardiovascular disease predominantly includes coronary heart disease (CHD) and stroke, results in high morbidity and mortality. MicroRNA-143-3p (miR-143-3p) is a tumor suppressor and is involved in many cancers. However, the role and mechanism of miR-143-3p in coronary heart disease is still unclear. In this study, we identified that miR-143-3p was up-regulated in rabbit CHD model. The results of TargetScan and the dual luciferase reporter assay indicated that KLLN (killin, p53 regulated DNA replication inhibitor) was a direct target of miR-143-3p. Besides, we revealed that KLLN was down-regulated in rabbit coronary heart disease model. In addition, we found that the related-markers of CHD such as TC (total cholesterol), TG (triglyceride), and LDLC (low-density lipoprotein cholesterol) in the model group were significantly increased than that in the control group. And compared with the model group, miR-143-3p inhibitor significantly reduced TC, TG, LDLC expression, while miR-143-3p mimic further increased the expression of TC, TG, and LDLC. We next found that miR-143-3p mimic promoted cell viability and migration of vascular smooth muscle cells, inhibited apoptosis; and these changes were reversed by KLLN-plasmid. And miR-143-3p inhibitor had the counter effects. Our study provided a new target for the treatment of CHD and deserves further study.

Background: Patients with chronic rheumatic heart disease (CRHD) have concomitant coronary artery disease (CAD), but the model to detect coexistent coronary artery stenosis prior to surgery has not been validated. Our study investigated whether the Framingham Risk Score (FRS) is a valid predictor of CAD in patients undergoing surgery for CRHD. Methods: A total of 989 rheumatic patients were enrolled between 2005 and 2010. They were subdivided into two groups according to coronary angiography (CAG) results to identify potential factors in the development of CAD. Finally, all patients were assessed using the FRS to examine the association between the 10-year cardiovascular disease (CVD) risk and CAD. Results: There were statistically significant inter-group differences in terms of age, sex, smoking, hypertension, bypass surgery and cardiac function in the New York Heart Association (NYHA) classification status (p Conclusions: The FRS model can accurately predict the prevalence of significant CAD and can reliably identify low-risk patients in whom routine pre-surgical angiography could be avoided.

The properties of InP grown by solid source molecular beam epitaxy have been studied concerning electron mobility in correlation with surface morphology and carrier concentration. The surface roughness and carrier concentration exhibit pronounced dependences on growth temperature and V/III flux ratio. A growth regime for a smooth surface and a high electron mobility is determined with growth temperature from 364– 390 ∘ C and V/III flux ratio from 2.4 to 3.5. A InP film with maximum electron mobility of 4.57 × 10 4 cm 2 / V s at 77 K has been achieved.

To explore the relationship between the apolipoprotein ApoA1-75 bp polymorphism and risk for dyslipidemia and coronary artery disease (CAD).A total of 723 patients (mean age (62.4 ± 10.2) years old) admitted to Guangdong General Hospital from 2011 to 2013 were enrolled. They were subdivided into CAD group (n = 444) and non-CAD (n = 279) group according to the result of coronary angiography (CAG). Clinical data including the profiles of lipids, -75 bp gene polymorphisms and Gensini scores were analyzed to determine the correlation between -75 bp gene polymorphisms, lipid profile and CAD.Frequency of male gender, history of diabetes and smoking, TC, TG, LDL-C and ApoB level were significantly higher and HDL-C level was significantly lower in CAD group than in non-CAD group (all P0.05). Frequency of A allele was significantly lower in CAD group than in non-CAD group (43.7% (194/444) vs. 56.6% (158/279) , P = 0.003). The ApoA1-75 bp gene polymorphism was significantly correlated with CAD (P0.005). Multivariate logistic regression analysis showed that -75 bp gene polymorphism mutation (OR = 0.649, P = 0.021) is an independent protective factor for coronary heart disease.ApoA1-75 bp gene polymorphism is linked with risk of dyslipidemia and CAD.

The effects of annealing time and Si cap layer thickness: on the thermal stability of the Si/SiGe/Si heterostructures deposited by disilane and solid-Ge molecule beam epitaxy were investigated. It is found that in the same strain state of the SiGe layers the annealing time decreases with increasing Si cap layer thickness. This effect is analyzed by a force-balance theory and an equation has been obtained to characterize the relation between the annealing time and the Si cap layer thickness. (C) 2001 Elsevier Science B.V. All rights reserved.

We have studied the growth of GaInNAs/GaAs quantum well (QW) by molecular beam epitaxy using a DC plasma as the N sourer. The N concentration was independent of the As pressure and the In concentration, but inversely proportional to the growth rate. It was almost independent of T, over the range of 400-500 degreesC, but dropped rapidly when T-g exceeded 500 degreesC. Thermally-activated N surface segregation is considered to account for the strong falloff of the N concentration. As increasing N concentration, the steep absorption edge of the photovoltage spectra of GaInNAs/GaAs QW became gentle, the full-width at half-maximum of the photoluminescence (PL) peal; increased rapidly, and a so-called S-shaped temperature dependence of PL peak energy showed up. All these were attributed to the increasing localized state as N concentration. Ion-induced damage was one of the origins of the localized state. A rapid thermal annealing procedure could effectively remote the localized state. (C) 2001 Elsevier Science D.V. All rights reserved.

Three n-p-n Si/SiGe/Si heterostructures with different layer thickness and doping concentration have been grown by a home-made gas source molecular-beam epitaxy (GSMBE) system using phosphine (PH3) and diborane (B2H6) as n-and p-type in situ doping sources, respectively. Heterojunction bipolar transistors (HBTs) have been fabricated using these structures and a current gain of 40 at 300 K and 62 at 77 K have been obtained. The influence of thickness and doping concentration of the deposited layers on the current gain of the HBTs is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.

As reported by other authors, we have also observed that the Si growth rate decreases with increasing phosphine (PH3) flow rate in gas source-Si molecular beam epitaxy using phosphorous (P) as a n-type dopant. Why small quantity PH3 can affect Si growth rate? Up to now, the quantitative characterization of PH3 flow influence on Si growth rate is little known. In this letter, the PH, influence will be analyzed in detail and a model considering strong P surface segregation and its absorption of hydrogen will be proposed to characterize the effect. (C) 2000 Elsevier Science B.V. All rights reserved.

We study the apparent substrate temperature oscillation during the whole growth of MBE-VCSEL. The accurate growth rate and mode wavelength are measured during the growth. The InGaAs-GaAs VCSEL with threshold current less than 200 /spl mu/A was achieved.

A GaInNAs/GaAs multiple quantum well (MQW) resonant-cavity enhanced (RCE) photodetector operating at 1.3 mum with the full-width at half-maximum of 5.5 nm was demonstrated. The GaInNAs RCE photodetector was grown by molecular-beam epitaxy using an ion-removed dc-plasma cell as nitrogen source. GaInNAs/GaAs MQW shows a strong exciton peak at room temperature that is very beneficial for applications in long-wavelength absorption devices. For a 100-mum diameter RCE photodetector, the dark current is 20 and 32 pA at biases of 0 and 6 V, respectively, and the breakdown voltage is -18 V. The measured 3-dB bandwidth is 308 MHz. The reasons resulting in the poor high speed property were analyzed. The tunable wavelength of 18 nm with the angle of incident light was observed.

The growth of GalnNAs/GaAs quantum well (QW) has been investigated by solid-source molecular beam epitaxy (MBE). N was introduced by a dc-active plasma source. Highest N concentration of 2.6% in GaInNAs/GaAs QW was obtained, corresponding to the photoluminescence peak wavelength of 1.57 mum at 10K. The nitrogen incorporation behavior in MBE growth and the quality improvement of the QW have been studied in detail. 1.3 mum GaInNAs/GaAs SQW laser and MQW resonant-cavity enhanced photodetector have been achieved.

The growth of Ga(In)NAs/GaAs is investigated by DC plasma-assisted MBE. The N incorporation, composition fluctuations and strain relaxation are characterized by X-ray diffraction measurements and dynamical simulations. /spl delta/-GaN/sub x/As/sub 1-x//GaAs superlattices and GaN/sub x/As/sub 1-x/ alloys of good quality are obtained through optimizing the growth conditions. Rapid-thermal annealing can improve the quality of Ga(In)NAs/GaAs significantly.

The structures of InGaAs/GaAs strained QW vertical cavity suurface-emitting lasers with low threshold current have been grown on tilted substrate by a modificatoy MBE system. The VCSEL structure contains 23.5 pairs n-type DBR , a strained InGaAs/GaAs 3QW active region ,and 20.5 pairs p-type DBR. The emission wavelength of InxGaixAs IGaAs QW lasers as a function of indium contents (x) and QW width has been studied theoretically and experimentally. The experimental results compared with theoretical calcuulation were in good agreement. The device measurements showed that room temperature CW operation of VCSEL has been achieved with the threshold current as low as 0.7 mA at 9430 A wavelength, and quantum efficiency above 12%.

A new type of strained InGaAs/GaAs ridge quantum wires (QWRs) structure has been proposed and fabricated firstly by MBE growth on patterned substrate. High resolution scanning electron microscope studies show that these ridge structures were formed with top and side faces. The photoluminescence measurements indicated that the lateral quantum confinement effects of the ridge-QWRs caused a blue-shift of the quantum confined energy, which agrees with the approximate calculations for the strained-ridge-QWR structure using Kronig-Penney model. This strained-ridge-QWRs consists of three aspects of lateral confinement effects. Firstly the thickness of ridge quantum wells on the ridge top is larger than that on the side surfaces; secondly the Indium concentrations on the ridge-top region is higher than that on the side region; thirdly the strain effects lead to a larger energy gaps in side plane than that in the ridge top. The above three factors were incorporated to enhance the confinement effects on the lateral motion of carriers in strained ridge QWRs.

The purity of GaAs grown by MBE was improved significantly when the MBE system was modified. The AlGaAs/GaAs quantum well heterostructures for mid-infrared detectors and two color infrared detector and InGaAs/GaAs quantum well heterostructure for vertical cavity surface emitting laser were grown successfully.