The possible impact of the universal two-child policy on pregnancy outcomes

PURPOSE

The implementation of the universal two-child policy contributes to adverse pregnancy outcomes, but how the policy change leads to adverse pregnancy outcomes is not well elaborated. In this study, we aimed to compare maternal characteristics and complications, accessed the change in the proportion of maternal characteristics and maternal complications, and evaluated the mediation of maternal characteristics on maternal complications.

METHODS

Demographic and clinical data of three-level sample facilities were extracted from China's National Maternity Near Miss Obstetrics Surveillance System from Jan 1, 2012 to May 31, 2021. The associations between the universal two-child policy and maternal risk factors, the universal two-child policy and maternal complications, and maternal risk factors and maternal complications were evaluated using multivariate logistic regression analyses, with odds ratios (ORs) and 95% confidence intervals (CIs). Mediation analysis was used to estimate the potential mediation effects on the associations between the policy and maternal complications. Population-attributable fractions (PAF) were conducted to quantify the maternal complications burden attributable to the implementation of the universal two-child policy.

RESULTS

In the context of the universal two-child policy, the incidence of maternal near miss, antepartum or intrapartum complication, and post-partum complication increased at municipal- and county-level sample facilities. After adjusting for covariables, there were significant associations between the universal two-child policy and maternal risk factors (P < 0.001), the universal two-child policy and an increased risk of maternal complications (P < 0.001), and maternal risk factors and maternal complications(P < 0.001). The effects of the universal two-child policy on maternal near miss and medical disease were significantly mediated by maternal risk factors with mediation proportions of 19.77% and 4.07% at the municipal-level sample facility, and mediation proportions for 2.72% at the county-level sample facility on medical disease. The universal two-child policy contributed 19.34%, 5.82%, 8.29%, and 46.19% in the incidence of the maternal near miss, antepartum or intrapartum complication, post-partum complication, and medical disease at municipal-level sample facility, respectively. The corresponding PAF% at county-level sample facility was 40.49% for maternal near miss, 32.39% for the antepartum or intrapartum complication, 61.44% for post-partum complication, and 77.72% for medical disease. For provincial-level sample facility, the incidence of maternal near miss, antepartum or intrapartum complications, and medical diseases decreased (P < 0.05) and no statistically significant difference occurred in the incidence of post-partum complications.

CONCLUSIONS

In the context of the universal two-child policy, the incidence of maternal near miss, antepartum or intrapartum complication, and post-partum complication increased at municipal- and county-level sample facility. Maternal risk factors may play a mediating role in the effect of policy change and maternal complications. Provincial hospitals have been able to improve the quality of perinatal health care and reduce adverse pregnancy outcomes by adjusting their obstetric service strategies in the context of the new birth policy.

[Analysis of clinical features and prognosis of acute severe autoimmune hepatitis]

Objective: To analyze the clinical features and prognosis of acute severe autoimmune hepatitis (AIH). Methods: A retrospective analysis of the clinical data of patients with acute severe AIH admitted to our hospital from 2008 to 2019 was divided into acute AIH (A-AIH) and chronic acute AIH (AC-AIH) according to the presence or absence of liver diseases. Patients' general condition, liver biochemistry, immunology, histological features of liver, hormonal therapies prognosis and related factors were analyzed. Results: A total of 41 cases [39 females, age (54.24 ± 10.55) years] were collected. Alanine aminotransferase (ALT) and total bilirubin (TBil) were significantly increased, and the international normalized ratio (INR) was > 1.5. Acute lobular inflammation was the feature of acute and severe AIH in the histology of liver. The serum IgG level was (28.36 ± 8.35) g / L. The positive rate of antinuclear antibody (ANA) and anti-smooth muscle antibody (ASMA) was 82.9%, and 17.1%, respectively. Over 70% of acute severe AIHs were AC-AIH. The duration of onset of AC-AIH was > 8 weeks, while most A-AIHs < 8 weeks, and the differences between the two groups were statistically significant (P = 0.001). The mortality rate within 30 days after hormonal treatment was 19.5%. There were statistically significant differences in TBil, Model for End-Stage Liver Disease (MELD) score and leukocyte count between the death and survival group. Conclusion: The mortality rate in acute severe AIH is high, and most of them have the basis of chronic liver disease. Serum IgG level, autoantibodies and acute lobular inflammation are important factors for diagnosis. The prognosis of hormonal therapy is related to the patients' condition and course of disease.

[Radiofrequency catheter ablation of ventricular tachycardia in patients post surgical repair of tetralogy of Fallot]

Objective: To investigate the clinical and electrophysiological features of ventricular tachycardia (VT) in tetralogy of Fallot (TOF) patients post surgical repair (rTOF) and to analyze the therapeutic effect and prognosis of radiofrequency ablation of rTOF-VT. Methods: This is a retrospective study. Consecutive patients with rTOF-VT, who were treated in Fuwai Hospital from January 2015 to March 2020, were enrolled. All the patients underwent right ventricular voltage mapping following routine cardiac electrophysiological examination, followed by linear or homogenizing radiofrequency ablation based on the low-voltage substrate. The clinical features, 3-dimentional electrophysiological substrate mapping, radiofrequency ablation and long-term prognosis of the enrolled patients were analyzed. Acute ablation success was defined as completion of linear or homogenizing ablation or intraoperative evoked VT as destination of the procedure. Patients were followed up at 3 and 6 months post operation and every year thereafter. The endpoints were sudden cardiac death (SCD) and recurrence of ventricular tachycardia. Results: A total of 20 patients with rTOF-VT were enrolled including 14 males with an age of (35.8±11.8) years. The electrocardiogram identified 23 types of ventricular tachycardia, 19 of which were originated from right ventricular inflow tract outlet. The most common clinical manifestations were heart murmur (19 cases, 95%) and syncope (4 cases, 25%). Electroanatomical substrate mapping was performed in 20 patients and evidenced localized or diffuse scar or low-voltage area of right ventricle. Intraoperative electrophysiological tests provoked ventricular tachycardia in 6 patients (30%), including 5 patients with hemodynamics disturbance. The acute success rate of radiofrequency ablation was 95% (19/20). The follow-up time was (31.1±17.7) months and the recurrence rate of ventricular tachycardia was 30% during follow-up period and 5 cases received repeat radiofrequency ablation and there was no recurrent ventricular tachycardia during follow-up post repeat radiofrequency ablation. Conclusions: The voltage substrate mapping under sinus rhythm is a feasible mapping method for rTOF-VT. Linear or flaky radiofrequency ablation of the slow conduction zone is safe and effective treatment strategy, the recurrence rate after the first radiofrequency ablation is still high, and the effectiveness of repeat radiofrequency ablation is satisfactory in this patient cohort.

[Current status and quality analysis of interventional therapy for patients with atrial fibrillation in China]

Objective: To define the current status and analyze the medical quality of interventional therapy for patients with atrial fibrillation (AF) in China. Methods: This survey was performed in all seven large regions of China, one to three regional major medical centers were selected from each region. Medical records of patients underwent interventional therapy for AF in the year 2017 were randomly inspected. CHA2DS2-VASc score, prescribed anticoagulant after ablation, indication of left atrial appendage occlusion (LAAO), and complications in the medical records were analyzed. Results: A total of 10 800 AF catheter ablations and 447 LAAOs were performed in 17 regional medical centers in 2017. There were 10/17 centers performing AF catheter ablation<500 cases and 7/17 centers performing LAAO<20 cases. A total of 1 347 cases of catheter ablation and 160 cases of LAAO were selected for further analysis. Among all selected cases, 15.8% (238/1 505) non-valvar AF cases recorded CHA2DS2-VASc scores. The anticoagulation rate after AF catheter ablation was 98.6% (1 328/1 347), anticoagulation rate was higher than 90% in 16 out of 17 centers. The complication and severe complication rates of AF catheter ablation were 0.9% (12/1 347) and 0.4% (5/1 347), respectively. The differences of complication and severe complication rates in AF catheter ablation were similar between centers performing<500 cases and centers performing ≥500 cases (0.5% (2/413) vs. 1.1% (10/934), P>0.05; 0.5% (2/413) vs. 0.3% (3/934), P>0.05). The coincidence rate of LAAO indication was 81.3% (130/160), and the rate was higher in center performing ≥20 cases than in centers performing<20 cases (84.8% (106/125) vs. 68.6% (24/35), P<0.05). The complication and severe complication rates of LAAO were 3.1% (5/160) and 1.9% (3/160). The rate of complications in LAAO was higher in center performing<20 cases than in centers performing ≥20 cases (8.6% (3/35) vs. 1.6% (2/125), P<0.05), and there was no significant difference in severe complication rate (5.7% (2/35) vs. 0.8% (1/125), P>0.05). Conclusions: Interventional therapy for AF in China is generally standardized and safe. The overall incidence of complications post AF interventional ablation is low, the anticoagulation rate after AF catheter ablation is high, and the adherence rate of LAAO indication is fair. The indicators mentioned above vary widely among centers.

[Analysis of treatment modalities and prognosis of patients with gallbladder cancer in China from 2010 to 2017]

Objective: To evaluate the clinical characteristics and prognosis of gallbladder cancer (GBC) patients in China. Methods: This retrospective multicenter cohort study enrolled 3 528 consecutive GBC patients diagnosed between January 2010 to December 2017 in 15 hospitals from 10 provinces. There were 1 345 (38.12%) males and 2 183 (61.88%) females.The age of diagnosis was (63.7±10.8) years old (range: 26 to 99 years old) .There were 213 patients (6.04%) in stage 0 to Ⅰ, whereas 1 059 (30.02%) in stage Ⅱ to Ⅲ, 1 874 (53.12%) in stage Ⅳ, and 382 (10.83%) unavailable. Surgery was performed on 2 255 patients (63.92%) . Three hundred and thirty-six patients received chemotherapy or radiotherapy (9.52%; of which 172 were palliative); 1 101 (31.21%) received only supportive treatment.The patient source, treatment and surgery, pathology, concomitant gallstone, and prognosis were analyzed. Results: Among the 3 528 GBC patients, 959 (27.18%) were from East China, 603 (17.09%) from East-North China, 1 533 (43.45%) from Central China, and 433(12.27%) from West China. Among the 1 578 resectable tumor, 665 (42.14%) underwent radical surgery, 913 (57.86%) underwent surgery that failed to follow the guidelines.Eight hundred and ninety-one (56.46%) patients were diagnosed before surgery, 254 (16.10%) during surgery, and 381 (24.14%) after surgery (time point of diagnosis couldn't be determined in 52 patients) .Among the 1 578 patients with resectable tumor, 759 (48.10%) had concomitant gallstone.Among the 665 patients underwent radical surgery, 69 (10.4%) showed positive resection margin, 510 (76.7%) showed negative resection margin, and 86 (12.9%) unreported margin status.The 5-year overall survival rate (5yOS) for the 3 528-patient cohort was 23.0%.The 5yOS for patients with resectable tumor was 39.6%, for patients with stage ⅣB tumor without surgery was 5.4%, and for patients with stage ⅣB tumor underwent palliative surgery was 4.7%. Conclusions: More than half GBC patients in China are diagnosed in stage Ⅳ.Curative intent surgery is valuable in improving prognosis of resectable GBC.The treatment of GBC needs further standardization.Effective comprehensive treatment for GBC is in urgent need.

Prediction of vaginal birth after cesarean delivery in Southeast China: a retrospective cohort study

BACKGROUND

We aimed to develop and validate a nomogram for effective prediction of vaginal birth after cesarean (VBAC) and guide future clinical application.

METHODS

We retrospectively analyzed data from hospitalized pregnant women who underwent trial of labor after cesarean (TOLAC), at the Fujian Provincial Maternity and Children's Hospital, between October 2015 and October 2017. Briefly, we included singleton pregnant women, at a gestational age above 37 weeks who underwent a primary cesarean section, in the study. We then extracted their sociodemographic data and clinical characteristics, and randomly divided the samples into training and validation sets. We employed the least absolute shrinkage and selection operator (LASSO) regression to select variables and construct VBAC success rate in the training set. Thereafter, we validated the nomogram using the concordance index (C-index), decision curve analysis (DCA), and calibration curves. Finally, we adopted the Grobman's model to perform comparisons with published VBAC prediction models.

RESULTS

Among the 708 pregnant women included according to inclusion criteria, 586 (82.77%) patients were successfully for VBAC. Multivariate logistic regression models revealed that maternal height (OR, 1.11; 95% CI, 1.04 to 1.19), maternal BMI at delivery (OR, 0.89; 95% CI, 0.79 to 1.00), fundal height (OR, 0.71; 95% CI, 0.58 to 0.88), cervix Bishop score (OR, 3.27; 95% CI, 2.49 to 4.45), maternal age at delivery (OR, 0.90; 95% CI, 0.82 to 0.98), gestational age (OR, 0.33; 95% CI, 0.17 to 0.62) and history of vaginal delivery (OR, 2.92; 95% CI, 1.42 to 6.48) were independently associated with successful VBAC. The constructed predictive model showed better discrimination than that from the Grobman's model in the validation series (c-index 0.906 VS 0.694, respectively). On the other hand, decision curve analysis revealed that the new model had better clinical net benefits than the Grobman's model.

CONCLUSIONS

VBAC will aid in reducing the rate of cesarean sections in China. In clinical practice, the TOLAC prediction model will help improve VBAC's success rate, owing to its contribution to reducing secondary cesarean section.

[Clinical characteristics of cardiomyopathies complicated with ventricular thrombosis]

Objective: To summarize the clinical characteristics of cardiomyopathy complicated with ventricular thrombosis. Methods: The clinical data of inpatients suffered from cardiomyopathy complicated with ventricular thrombosis in Fuwai Hospital between January 2015 and May 2019 were analyzed retrospectively. Results: A total of 125 cases were reviewed, and 24.8% were female. Dilated cardiomyopathy was the most common disease (62.4%), followed by arrhythmogenic right ventricular cardiomyopathy (ARVC) (13.6%) and hypertrophic cardiomyopathy (11.2%). There were 74.4% thrombosis in left ventricle, 12.8% in right ventricle and 12.8% in biventricle. The proportions of right ventricle thrombosis were higher in ARVC than in other cardiomyopathies (52.9% vs 6.5%, P<0.01). The majority suffered from cardiac function New York Heart Association (NYHA) Class Ⅲ (45.6%) and class Ⅳ (39.2%). The ratio of NYHA Class Ⅳ was higher in female patients than in male ones (25.8% vs 10.6%, P<0.05). In lab detection, positive results of D-Dimer and N terminal-pro B type natriuretic peptide (NT-proBNP) accounted for 72.8% and 97.6%, respectively. There were 2.5% patients died in the hospital or discharged because of the worsening of illness, the chances were higher in female than male patients (9.7% vs 0, P<0.01). Among these patients, one succumbed to massive ischemic stroke caused by ventricular thrombus detachment under standard anticoagulation therapy. Conclusions: Dilated cardiomyopathy is the most common cardiomyopathy complicated with ventricular thrombosis. The most common location of thrombosis is left ventricle. Right ventricle thrombosis is more common in ARVC. The majority suffer from moderate or severe cardiac dysfunction. Higer proportion of female patients suffer from anemia, severe condition and poor prognosis.

The prognostic value of the 8th edition of the American Joint Committee on Cancer (AJCC) staging system in triple-negative breast cancer

The American Joint Committee on Cancer (AJCC) released its 8th edition of cancer staging implemented in early 2018. This study aims to compare anatomic staging (AS) with prognostic staging (PS) based on the updated AJCC 8th edition staging manual. A retrospective single-center analysis of 313 triple-negative breast invasive ductal carcinoma patients who received surgery at department of breast surgery in the Fourth Hospital of Hebei Medical University from 01/2010 -12/2012 was performed. All cases were restaged using the AJCC 8th edition AS and PS system. The 7-year disease-free survival (DFS) and the 7-year overall survival (OS) rates were 76.30% and 78.27%, respectively. Applying the PS system, 277 (88.5%) patients of the AS groups were upstaged to the PS groups, 31 cases with IIIC and 5 cases with IV unchanged (11.5%) and no cases downstaged. Both 7-year DFS and 7-year OS were significantly different in the different AS and PS groups (all, p<0.001). The PS system was found to provide better prognostic information in patients with AS group IIB. A total of 43 patients with AS group IIB were upstaged by PS system, in which 30 patients were +2 upstaged to PS IIIB, and 13 patients were +3 upstaged to PS IIIC. PS IIIB and IIIC from AS IIB had significant differences in 7-year DFS (χ2=5.628, p=0.014) and 7-year OS (χ2=6.037, p=0.018). Both AS and PS systems proposed in the 8th edition of the AJCC breast cancer staging manual had prognostic value in TNBC. Moreover, the PS system predicts clinical outcomes of TNBC patients more accurately than the traditional AS system.

Diode-wing-pumped electro-optically Q-switched 2 μm laser with pulse energy scaling over ten millijoules

Characteristics of diode-wing-pumped highly efficient Tm:LuAG lasers running both in continuous wave (CW) and electro-optical Q-switching regimes have been investigated. Using a simple plane-plane cavity, a maximum CW output power of 8.5 W has been achieved with a corresponding slope efficiency of 44.5% by "wing pumping" at 790 nm. With a V-shaped cavity, a diode-wing-pumped MgO:LiNbO₃ crystal based electro-optically Q-switched Tm:LuAG laser at 2022.9 nm delivered a maximum pulse energy of 10.8 mJ and a minimum pulse width of 52 ns at a corresponding repetition rate of 100 Hz. To the best of our knowledge, the achieved CW output power and Q-switched pulse energy have both set records for all-solid-state Tm:LuAG lasers, which well reveals an efficient way to generate high-power and high-energy lasers at 2 μm wavelength.

[Initial experience of catheter ablation of ventricular tachycardia originate from endocardium via direct ventricle puncture access in patients underwent mechanical valve implantation]

Objective: To evaluate the results of catheter ablation of ventricular tachycardia (VT) via direct ventricle puncture access in patients without traditional approach. Methods: Two idiopathic left fasicular VT patients with mechanical aortic and mitrial valve repalcement and 1 patient with right ventricular originated VT post mechanical tricuspid valve repalcement from March 2010 to July 2012 in Fuwai hospital were enrolled in this study. For left fasicular VT patients, catheter ablation was performed using transapical left ventricular access via minithoracotomy. For the patient with right ventricular originated VT, catheter ablation was performed via percutaneous right ventricle puncture at xiphoid. Abaltion was guided under EnSite NavX mapping system. The feasibility of VT ablation via direct ventricle puncture access and long-term VT recurrence were investigated. Results: Catheter ablation was successful in all patients, and all clinical VTs were eliminated. The procedure time was 53, 62 and 74 minutes respectively with radiation time 11, 16 and 20 minutes. The ablation time was 130, 170 and 240 seconds individually. No procedure related complication occurred. After a follow-up time of 76, 55 and 82 months respectively, no VT recurrence was found in patients with left fasicular VT. New-onset VT with different morphology with previous VT was recorded in the patient with right ventricular originated VT, subcutaneous implantable defibrillator was implanted finally in this patient. Conclusions: For patients with endocardial origined ventricular arrhythmias which could not be ablated via traditional approaches, direct ventricle puncture access with hybrid techniques provides a new approach foreliminating VTs in these patients.

[Novel biomarkers for latent tuberculosis infection by plasma proteomic profiling]

OBJECTIVE

To screen specific biomarkers for latent tuberculosis infection by comparing the plasma proteomic profiling between latent tuberculosis infection and healthy controls.

METHODS

The plasma proteins from 15 cases with latent tuberculosis infection and 15 healthy controls were detected by the label-free quantitative proteomic technology. Differential expressed proteins were analyzed by GO, KEGG, and BiNGO analysis. Student's t test was used to analyze the differential expression between 2 groups.

RESULTS

Twenty-three candidate proteins were identified, among which 15 proteins were downregulated (<0.5-fold at P<0.05) and 8 proteins were upregulated (>2.0-fold at P<0.05) in the latent tuberculosis infection group. Bioinformatic analysis revealed 3 proteins AAT, C3 and C4A to be the most significant.

CONCLUSION

There were differential plasma protein profiles between latent tuberculosis infection and healthy controls. Candidate proteins AAT, C3 and C4A were promising biomarkers for discriminating cases with latent tuberculosis infection from healthy persons.

Influence of wavefront aberration on the imaging performance of the solar grating spectrometer

The solar grating spectrometer is an important tool to study the thermodynamic properties of the solar atmosphere with different height distribution, but its imaging performance will be degraded by the wavefront aberration. On the other hand, narrow slit of the grating spectrometer will filter the wavefront aberration to a certain extent. In this paper, the mathematical relation between the wavefront aberration and the imaging performance of the grating spectrometer is derived. The numerical simulation is performed and is validated by the experiment. The results demonstrate that: The influence of the wavefront aberration with the different types and magnitudes on the spectral resolution and the energy utilization is different. The influence of the different slits on the wavefront aberrations is different. Generally, the smaller the slit is, the better the spectral resolution is. However, this is not true for the low-frequency dominated aberration, e.g. the defocus, since its low frequency will also be blocked by the narrow slit. If the influence of the filter slit on the wavefront aberration cannot be taken into account, it will lead to adaptive optics over-compensation.

Diode-pumped continuous wave tunable and graphene Q-switched Tm:LSO lasers

We have investigated the lasing characteristics of Tm:LSO crystal in three operation regimes: continuous wave (CW), wavelength tunable and passive Q-switching based on graphene. In CW regime, a maximum output power of 0.65 W at 2054.9 nm with a slope efficiency of 21% was achieved. With a quartz plate, a broad wavelength tunable range of 145 nm was obtained, corresponding to a FWHM of 100 nm. By using a graphene saturable absorber mirror, the passively Q-switched Tm:LSO laser produced pulses with duration of 7.8 μs at 2030.8 nm under a repetition rate of 7.6 kHz, corresponding to pulse energy of 14.0 μJ.

Mode-locked Tm,Ho:YAP laser around 2.1 μm

A passively mode-locked Tm,Ho:YAP laser around 2.1 μm wavelength employing a semiconductor saturable absorber mirror is demonstrated. Stable continuous wave mode-locking operation was achieved at variable center wavelengths of 2036.5 nm, 2064.5 nm, 2095.5 nm, 2103.5 nm, and 2130 nm, respectively. Pulses as short as 40.4 ps were obtained at 2064.5 nm with a spectral FWHM of 0.5 nm at output powers of 132 mW and a repetition rate around 107 MHz. A maximum output power of 238 mW was obtained at 2130 nm with a pulse duration of 66 ps.

Passively Q-switched Nd:Sc0.2Y0.8SiO5 dual-wavelength laser with the orthogonally polarized output

We have demonstrated a laser-diode pumped continuous-wave (CW) and passively Q-switched laser with a Nd:Sc(0.2)Y(0.8)SiO(5) (Nd:SYSO) crystal for the first time. In the CW operation, the laser was found to oscillate in tri-wavelength regime at 1074.8 nm, 1076.6 nm and 1078.2 nm, respectively. The maximum CW output power of 1.96 W was obtained, giving an optical-to-optical conversion efficiency of 35% and a slope efficiency of 39%. Using either Cr(4+):YAG or V(3+):YAG crystal as saturable absorber, stable passively Q-switched laser was obtained at dual-wavelength of 1074.8 nm and 1078.2 nm with orthogonal-polarization. The maximum average output power, pulse repetition rate, and shortest pulse width were 1.03 W, 50 kHz, and 24 ns, respectively. The passively Q-switched dual-wavelength laser could be potentially used as a source for generation of terahertz radiation.

Efficient continuous wave and passively mode-locked Tm-doped crystalline silicate laser

An efficient continuous wave and passively mode-locked thulium-doped oxyorthosilicate Tm:LuYSiO5 laser is demonstrated. A maximum slope efficiency of 56.3% is obtained at 2057.4 nm in continuous wave operation regime. With an InGaAs quantum well SESAM, self-starting passively mode-locked Tm:LuYSiO5 laser is realized in the 1929 nm to 2065 nm spectral region. A maximum average output power of 130.2 mW with a pulse duration of 33.1 ps and a repetition rate of about 100 MHz is generated at 1984.1 nm. Pulses as short as 24.2 ps with an average output power of 100 mW are obtained with silicon prisms where used to manage the intracavity dispersion. The shortest pulse duration of about 19.6 ps is obtained with an average output power of 64.5 mW at 1944.3 nm.

Comparative investigations on continuous wave operation of a-cut and b-cut Tm,Ho:YAlO3 lasers at room temperature

The Tm,Ho:YAlO3 laser performance for two crystal orientations pumped by a wavelength tunable Ti:Sapphire laser is presented in this paper. An experimental investigation comparing a- and b-oriented Tm,Ho:YAlO3 crystals laser performance is demonstrated and discussed. Single- and multi-wavelength operations of Tm,Ho:YAlO3 lasers have been investigated in detail. The maximum output powers of 890 mW at 2119 nm for a-oriented Tm,Ho:YAlO3 crystal and 946 mW at 2103 nm for b-oriented Tm,Ho:YAlO3 crystal have been obtained, respectively. The two crystals show very similar performance in terms of output power and conversion efficiency, only that the b-cut Tm,Ho:YAP crystal demonstrates more regimes of multi-wavelength operations.

Study on three dimensional reconstruction of transesophageal echocardiographic images

Using biplane transesophageal echocardiography and the concept of three dimensional transthoracic echocardiography, we performed three dimensional reconstruction of transesophageal images of various clinicopathologic cases, including atrial septal defect, mitral stenosis, mitral valve prolapse and pulmonary stenosis. The hardware equipment and image processing flow chart of three dimensional reconstruction of transesophageal echocardiographic images are described. Our present study indicates that three dimensional reconstruction of transesophageal echocardiographic images could display multi-regional three dimensional structures of heart and great vessels, including superior vena cava, ascending aorta, right ventricular outflow tract, pulmonary artery and left heart, with clear, visual and stereoscopic imaging. The regional structures could be displayed at different levels of stereo-anatomic-sections and in different orientations of rotating stereo-images, which could provide accurate three dimensional anatomical information for cardiac stereo-morphological study and definition of spatial location and size of cardiac abnormalities.

Three-dimensional transesophageal echocardiography in the diagnosis of mitral valve prolapse

Because the anulus of the mitral valve is nonplanar in systole, false-positive diagnosis of mitral valve prolapse may result from two-dimensional transthoracic echocardiography. Because of the superior image quality of TEE, we used the three-dimensional TEE technique to evaluate the mitral valve in both normal subjects and patients with mitral valve prolapse and with ruptured chordae tendineae. After a conventional TEE examination, sequential images of longitudinal views were obtained by probe rotation. The images at 5-degree intervals were stored in machine cine memory loop; the special temporal images were selected with ECG gating and videorecorded. During the examination, 6 to 8 images of the left heart were recorded for later off-line, three-dimensional reconstruction. A total of 42 subjects were studied: 32 normal, 9 with mitral valve prolapse, and 1 with ruptured chordae tendineae. In normal subjects, three-dimensional TEE showed nonplanarity of the entire mitral valve, which assumes a saddle shape. In mitral valve prolapse, either the anterior or posterior leaflet protruded into the left atrium like a spoon; when both leaflets are involved, they prolapse like two spoons. The anterior and posterior leaflets coapted poorly, and there was a seam between them. In ruptured chordae tendineae the tip of the mitral leaflet protruded during systole into the left atrium far from the coaptation point and was perpendicular to the body of the mitral valve and parallel to the anterior and posterior walls of the left atrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical application of three-dimensional transesophageal echocardiography

Three-dimensional transesophageal echocardiography is a new and evolving cardiac imaging technique. We reported our experiences of its clinical applications in 59 patients. A series of special temporal longitudinal views were selected by the frame grabber. Then the computer connected each digitized endocardial surface of the longitudinal views according to their spatial position and reconstructed the three-dimensional, cardiac shaded picture with gray scale. The three-dimensional transesophageal echocardiographic images were divided into three areas. The right area was right anterior to the esophagus and included such structures as the superior vena cava, right atrium, interatrial septum, and left atrium; the size, shape, and location of an atrial septal defect could be clearly shown. In the middle area the origin and the course of the two great arteries could be visualized, thus facilitating the diagnosis of transposition of the great arteries; in patients with obstruction of the right ventricular outflow tract, the circular ridgelike narrowing in the right ventricle was clearly visualized. In the left area the contour and size of the left ventricle and left atrium and the shape and point of coaptation of the mitral valve could be demonstrated; in patients with mitral valve prolapse, part of either leaflet protruded into the left atrium and appeared as a spoonlike depression in the mitral valve. Other entities subjected to three-dimensional transesophageal echocardiographic reconstruction included cor triatriatum, left atrial myxoma, aneurysm of sinus of Valsalva, dissecting aortic aneurysm, mitral stenosis, mitral regurgitation, and mitral valve prolapse.(ABSTRACT TRUNCATED AT 250 WORDS)