[Optimization of perioperative treatment strategies for locally advanced esophageal squamous cell carcinoma from the perspective of tumor heterogeneity]

Recent advances in multimodality treatment offer excellent opportunities to rethink the paradigm of perioperative management for locally advanced esophageal squamous cell carcinoma. One treatment clearly doesn't fit all in terms of a broad disease spectrum. Individualized treatment of local control of bulky primary tumor burden (advanced T stage) or systemic control of nodal metastatic tumor burden (advanced N stage) is essential. Given that clinically applicable predictive biomarkers are still awaited, therapy selection guided by diverse phenotypes of tumor burden (T vs. N) is promising. Potential challenges regarding the use of immunotherapy may also boost this novel strategy in the future.

[Advances of immunotherapy-related biomarker in esophageal carcinoma]

Esophageal carcinoma is one of the most common malignant tumors in the world, with incidence and mortality rankings of 7th and 6th, respectively. In recent years, immunotherapy represented by immune checkpoint inhibitors of programmed death-1 and programmed death ligand 1 (PD-L1) has been introduced into clinical practice and has changed the treatment status of esophageal cancer. Although immunotherapy has provided long-term survival benefits for patients with advanced esophageal cancer and high pathological response rates in the neoadjuvant therapy, only a few of the patients have satisfactory therapeutic outcomes. Therefore, effective biomarkers for predicting immunotherapeutic effects are urgently needed to identify those patients who could benefit from immunotherapy. In this paper, we mainly discuss recent research advances of biomarkers related to the immunotherapy of esophageal cancer and the clinical application prospects of these biomarkers.

Recent progress of two-dimensional heterostructures for thermoelectric applications

The rapid development of synthesis and fabrication techniques has opened up a research upsurge in two-dimensional (2D) material heterostructures, which have received extensive attention due to their superior physical and chemical properties. Currently, thermoelectric energy conversion is an effective means to deal with the energy crisis and increasingly serious environmental pollution. Therefore, an in-depth understanding of thermoelectric transport properties in 2D heterostructures is crucial for the development of micro-nano energy devices. In this review, the recent progress of 2D heterostructures for thermoelectric applications is summarized in detail. Firstly, we systematically introduce diverse theoretical simulations and experimental measurements of the thermoelectric properties of 2D heterostructures. Then, the thermoelectric applications and performance regulation of several common 2D materials, as well as in-plane heterostructures and van der Waals heterostructures, are also discussed. Finally, the challenges of improving the thermoelectric performance of 2D heterostructures materials are summarized, and related prospects are described.

Excellent Medium-Temperature Thermoelectric Performance of Monolayer BiOCl

Recently, a ternary-layered material BiOCl has elicited intense interest in photocatalysis, environmental remediation, and ultraviolet light detection because of its unique band gap of around 3.6 eV, low toxicity, and earth abundance. In particular, Gibson et al. reported a measurement of the in-plane thermal conductivity of BiOCl experimentally using a four-point-probe method [Science, 373, 1017-1022 (2021)], which is only 1.25 W/m K at 300 K. Motivated by the work, we studied the thermoelectric property of monolayer BiOCl using first-principles calculations combined with the Boltzmann transport equation. The calculated phonon thermal conductivity of monolayer BiOCl is 3 W/m K at 300 K, which is far below that of other promising 2D thermoelectric materials like graphyne and MoS₂. A comprehensive analysis of phonon modes is conducted to reveal the low thermal conductivity. Moreover, the maximal ZT value is as high as 1.8 at 300 K and 5.7 at 800 K for the p-type doping with the 2 × 10¹⁵ cm^-2 concentration. More importantly, we found that the thermoelectric efficiency of such 2D materials is significantly enhanced to 8 at 800 K by applying 1.5% tensile strain, which clearly outperforms that of the reported 2D thermoelectric material SnSe. The results shed light on the promising application in medium-temperature (600-900 K) thermoelectric devices.

Enhancement of thermoelectric performance in graphenylene nanoribbons by suppressing phonon thermal conductance: the role of phonon local resonance

Based on the method of non-equilibrium Green's function, we investigate the thermal transport and thermoelectric properties of graphenylene nanoribbons (GRNRs) with different width and chirality. The results show that the thermoelectric (TE) performance of GRNRs significantly increases with decreasing ribbon width, which stems from the reduction of thermal conductance. In addition, by changing the ribbon width and chirality, the figure of merit (ZT) can be controllably manipulated and maximized up to 0.45 at room temperature. Moreover, it is found that theZTvalue of GRNRs with branched structure can reach 1.8 at 300 K and 3.4 at 800 K owing to the phonon local resonance. Our findings here are of great importance for thermoelectric applications of GRNRs.

[Oligometastatic and oligoprogressive esophageal squamous cell carcinoma:clarifying conceptions and surgery perspectives]

The oligometastatic and oligoprogressive state has been a hot issue in cancer research. Its indolent tumor behavior, representing a novel therapeutic opportunity, has been identified as a clinical subtype in several malignancies. However, the clinical implications of the oligometastatic and oligoprogressive state in esophageal squamous cell carcinoma (ESCC) have not been thoroughly elucidated. There are still controversies regarding the existence of the oligometastatic state in ESCC, if the solitary regional lymph node metastasis should be viewed as oligoprogressive disease after esophagectomy, and the role of surgery and radiotherapy in ESCC oligometastatic disease. Despite many exciting contributions to the literature on these, further exploration is warranted. Thus, fostering the advance of research and scientific knowledge on the biological and prognostic characteristics scrupulously would facilitate personalizing treatment strategy for better outcomes.

[Application of multi-slice spiral CT refarmation reconstruction technique and DR photography of pneumoconiosis patients at stage three]

Objective: To investigate the value of CT multiplanar reconstruction (MPR) in the diagnosis of stage Ⅲ pneumoconiosis and complications. Methods: In September 2020, 94 patients with stage Ⅲ pneumoconiosis in Guangzhou 12th people's hospital were selected for digital radiography (DR) and MPR. The detection rate of the number of large shadows and the incidence of related complications were compared and analyzed. The counting data were expressed by frequency and percentage (%) , and the comparison was performed by chi square test. Results: 178 and 132 large shadows were detected in MPR and DR chest films respectively. Compared with Dr examination, MPR had higher detection rates of pneumoconiosis related complications such as pulmonary tuberculosis, emphysema, pleural thickening, adhesion, pneumonia, pleural effusion, enlargement of hilar and mediastinal lymph nodes and calcification (P<0.05) , There was no significant difference in the detection rate of pulmonary bullae (P>0.05) . Compared with Dr, MPR had a higher detection rate in the diagnosis of cavity, calcification, bronchiectasis and parascar emphysema (P<0.05) . Conclusion: MPR is better in detecting large shadow and complications of stage Ⅲpneumoconiosis, and has important value.

Thermal transport properties in monolayer group-IV binary compounds

New classes of two-dimensional (2D) materials beyond graphene are now attracting intense interest owing to their unique properties and functions. By combining first-principle calculation and the Boltzmann transport equation, we investigated the thermal transport properties of monolayer honeycomb structures of group-IV (C, Si, Ge, Sn) binary compounds. It is found that the thermal conductivity (κ) of these compounds span an enormously large range from 0.04 to 144.29 W m^-1 K^-1, demonstrating promising applications to nanoscale thermoelectrics and thermal management. The κ of low-buckled structures such as SiGe, SiSn and GeSn is lower than that of planar structures such as SiC, GeC and SnC, which can be ascribed to heavy atomic mass and broken in-plane reflection symmetry. Moreover, the κ of planar or low-buckled compounds with Sn atom is much lower than others, and the detailed origin for this phenomenon and contribution of different phonon modes to the κ are investigated. This work has fully studied the diversity of the thermal phenomenon and provides more options for application on thermal transport.

[Surgical treatment for esophageal cancer during the outbreak of COVID-19]

Since December 2019, unexplained pneumonia has appeared in Wuhan City, Hubei Province, and a new type of coronavirus infection was confirmed as COVID-19. COVID-19 spread rapidly nationwide and abroad. The COVID-19 has brought huge impacts to all the people and walks of life, especially to the medical and health systems. It has also brought great challenges to the treatment of patients with cancer. Esophageal cancer is a common malignant tumor in China and most of the patients are in the middle and advanced stage when diagnosed, with immunosuppressive and poor prognosis. The selection of surgical procedures and perioperative managements of esophageal cancer require all thoracic surgeons work together to figure out a reasonable system of surgical treatment and emergency response.

Thermal transport of carbon nanomaterials

The diversity of thermal transport properties in carbon nanomaterials enables them to be used in different thermal fields such as heat dissipation, thermal management, and thermoelectric conversion. In the past two decades, much effort has been devoted to study the thermal conductivities of different carbon nanomaterials. In this review, different theoretical methods and experimental techniques for investigating thermal transport in nanosystems are first summarized. Then, the thermal transport properties of various pure carbon nanomaterials including 1D carbon nanotubes, 2D graphene, 3D carbon foam, are reviewed in details and the associated underlying physical mechanisms are presented. Meanwhile, we discuss several important influences on the thermal conductivities of carbon nanomaterials, including size, structural defects, chemisorption and strain. Moreover, we introduce different nanostructuring pathways to manipulate the thermal conductivities of carbon-based nanocomposites and focus on the wave nature of phonons for controlling thermal transport. At last, we briefly review the potential applications of carbon nanomaterials in the fields of thermal devices and thermoelectric conversion.

Thermal Rectification in Asymmetric Graphene/Hexagonal Boron Nitride van der Waals Heterostructures

Graphene/hexagonal boron nitride (h-BN) heterostructures assembled by van der Waals (vdW) interactions show numerous unique physical properties such as quantum Hall effects and exotic correlated states, which have promising potential applications in the design of novel electronic devices. Understanding thermal transport in such junctions is critical to control the performance and stability of prospective nanodevices. In this work, using nonequilibrium molecular dynamics simulations, we systematically investigate the thermal transport in asymmetric graphene/h-BN vdW heterostructures. It is found that the heat prefers to flow from the monolayer to the multilayer regions, resulting in a significant thermal rectification (TR) effect. To determine the optimum conditions for TR, the influences of sample length, defect density, asymmetric degree, ambient temperature, and vdW interaction strength are studied. Particularly, we found that the TR ratio could be improved by about 1 order of magnitude via increasing the coupling strength from 1 to 10, which clearly distinguishes from the commonly held notion that the TR ratio is practically insensitive or even decreasing with the interaction strength. Detailed spectral analysis reveals that this unexpected increase of the TR ratio can be attributed to heavily modified phonon properties of encased graphene due to enhanced interlayer coupling. Our results elucidate the importance of vdW interactions to heat conduction in nanostructures.

Phonon transport in periodically and quasi-periodically modulated cylindrical nanowires

Phonon transport in periodically modulated cylindrical nanowire (PMCN) and quasi-periodically modulated cylindrical nanowire (QPMCN) is comparatively studied. It is shown that the transmission coefficient and thermal conductance for PMCN is greater than the corresponding values for QPMCN. At low frequencies, a wide stop-frequency gap due to the destructive interference between the incoming and back waves can be clearly observed here. For PMCN, such stop-frequency gap seems to be insensitive to the change of N (the periodic number). For QPMCN, however, its breadth increases with the increase of N (the Fibonacci number). When N is increased, the thermal conductance for PMCN presents a distinct change from the decrease to the constant, while QPMCN has a tendency of monotonous decrease. A brief discussion on these results is made.

[Technical specification for clinical application of critical ultrasonography]

Critical ultrasonography(CUS) is different from the traditional diagnostic ultrasound, the examiner and interpreter of the image are critical care medicine physicians. The core content of CUS is to evaluate the pathophysiological changes of organs and systems and etiology changes. With the idea of critical care medicine as the soul, it can integrate the above information and clinical information, bedside real-time diagnosis and titration treatment, and evaluate the therapeutic effect so as to improve the outcome. CUS is a traditional technique which is applied as a new application method. The consensus of experts on critical ultrasonography in China released in 2016 put forward consensus suggestions on the concept, implementation and application of CUS. It should be further emphasized that the accurate and objective assessment and implementation of CUS requires the standardization of ultrasound image acquisition and the need to establish a CUS procedure. At the same time, the standardized training for CUS accepted by critical care medicine physicians requires the application of technical specifications, and the establishment of technical specifications is the basis for the quality control and continuous improvement of CUS. Chinese Critical Ultrasound Study Group and Critical Hemodynamic Therapy Collabration Group, based on the rich experience of clinical practice in critical care and research, combined with the essence of CUS, to learn the traditional ultrasonic essence, established the clinical application technical specifications of CUS, including in five parts: basic view and relevant indicators to obtain in CUS; basic norms for viscera organ assessment and special assessment; standardized processes and systematic inspection programs; examples of CUS applications; CUS training and the application of qualification certification. The establishment of applied technology standard is helpful for standardized training and clinical correct implementation. It is helpful for clinical evaluation and correct guidance treatment, and is also helpful for quality control and continuous improvement of CUS application.

Anisotropic thermal conductivity in carbon honeycomb

Carbon honeycomb, a new kind of 3D carbon allotrope experimentally synthesized recently, has received much attention for its fascinating applications in electronic device and energy storage. In the present work, we perform equilibrium molecular dynamics (EMD) to study the thermal transport properties of carbon honeycombs with different chirality. It is found that the thermal conductivity along the honeycomb axis ([Formula: see text]) is three times larger than that normal to the axis ([Formula: see text]), which shows strong anisotropy reflecting their geometric anisotropy. Lattice dynamics calculations reveal that this anisotropy stems from the orientation-dependent phonon group velocities. Moreover, when ambient temperature ([Formula: see text]) increases from 200 K to 800 K, the [Formula: see text] dependence of [Formula: see text] is observed due to the enhanced Umklapp scattering. The detailed phonon spectra analyses indicate phonon group velocities are insensitive to the variation of ambient temperature, and the temperature dependence of the relaxation times of low-frequency phonons (<20 THz) follows [Formula: see text] behavior. Our results have a certain guiding significance to develop carbon honeycomb for effective thermal channeling devices.

[Experts consensus on the management of the right heart function in critically ill patients]

To establish the experts consensus on the right heart function management in critically ill patients. The panel of consensus was composed of 30 experts in critical care medicine who are all members of Critical Hemodynamic Therapy Collaboration Group (CHTC Group). Each statement was assessed based on the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) principle. Then the Delphi method was adopted by 52 experts to reassess all the statements. (1) Right heart function is prone to be affected in critically illness, which will result in a auto-exaggerated vicious cycle. (2) Right heart function management is a key step of the hemodynamic therapy in critically ill patients. (3) Fluid resuscitation means the process of fluid therapy through rapid adjustment of intravascular volume aiming to improve tissue perfusion. Reversed fluid resuscitation means reducing volume. (4) The right ventricle afterload should be taken into consideration when using stroke volume variation (SVV) or pulse pressure variation (PPV) to assess fluid responsiveness.(5)Volume overload alone could lead to septal displacement and damage the diastolic function of the left ventricle. (6) The Starling curve of the right ventricle is not the same as the one applied to the left ventricle,the judgement of the different states for the right ventricle is the key of volume management. (7) The alteration of right heart function has its own characteristics, volume assessment and adjustment is an important part of the treatment of right ventricular dysfunction (8) Right ventricular enlargement is the prerequisite for increased cardiac output during reversed fluid resuscitation; Nonetheless, right heart enlargement does not mandate reversed fluid resuscitation.(9)Increased pulmonary vascular resistance induced by a variety of factors could affect right heart function by obstructing the blood flow. (10) When pulmonary hypertension was detected in clinical scenario, the differentiation of critical care-related pulmonary hypertension should be a priority. (11) Attention should be paid to the change of right heart function before and after implementation of mechanical ventilation and adjustment of ventilator parameter. (12) The pulmonary arterial pressure should be monitored timingly when dealing with critical care-related pulmonary hypertension accompanied with circulatory failure.(13) The elevation of pulmonary aterial pressure should be taken into account in critical patients with acute right heart dysfunction. (14) Prone position ventilation is an important measure to reduce pulmonary vascular resistance when treating acute respiratory distress syndrome patients accompanied with acute cor pulmonale. (15) Attention should be paid to right ventricle-pulmonary artery coupling during the management of right heart function. (16) Right ventricular diastolic function is more prone to be affected in critically ill patients, the application of critical ultrasound is more conducive to quantitative assessment of right ventricular diastolic function. (17) As one of the parameters to assess the filling pressure of right heart, central venous pressure can be used to assess right heart diastolic function. (18). The early and prominent manifestation of non-focal cardiac tamponade is right ventricular diastolic involvement, the elevated right atrial pressure should be noticed. (19) The effect of increased intrathoracic pressure on right heart diastolic function should be valued. (20) Ttricuspid annular plane systolic excursion (TAPSE) is an important parameter that reflects right ventricular systolic function, and it is recommended as a general indicator of critically ill patient. (21) Circulation management with right heart protection as the core strategy is the key point of the treatment of acute respiratory distress syndrome. (22) Right heart function involvement after cardiac surgery is very common and should be highly valued. (23) Right ventricular dysfunction should not be considered as a routine excuse for maintaining higher central venous pressure. (24) When left ventricular dilation, attention should be paid to the effect of left ventricle on right ventricular diastolic function. (25) The impact of left ventricular function should be excluded when the contractility of the right ventricle is decreased. (26) When the right heart load increases acutely, the shunt between the left and right heart should be monitored. (27) Attention should be paid to the increase of central venous pressure caused by right ventricular dysfunction and its influence on microcirculation blood flow. (28) When the vasoactive drugs was used to reduce the pressure of pulmonary circulation, different effects on pulmonary and systemic circulation should be evaluated. (29) Right atrial pressure is an important factor affecting venous return. Attention should be paid to the influence of the pressure composition of the right atrium on the venous return. (30) Attention should be paid to the role of the right ventricle in the acute pulmonary edema. (31) Monitoring the difference between the mean systemic filling pressure and the right atrial pressure is helpful to determine whether the infusion increases the venous return. (32) Venous return resistance is often considered to be a insignificant factor that affects venous return, but attention should be paid to the effect of the specific pathophysiological status, such as intrathoracic hypertension, intra-abdominal hypertension and so on. Consensus can promote right heart function management in critically ill patients, optimize hemodynamic therapy, and even affect prognosis.

Anomalous thermal conductance of graphyne under lower temperature

The thermal transport properties of graphyne are investigated via equilibrium molecular dynamics (EMD) simulations and non-equilibrium Green's function (NEGF) method. It is found that the room-temperature thermal conductivity of graphyne is 93% lower than that of graphene with a similar size and decreases steeply with increasing the number of acetylenic linkages, which agrees with the results obtained by NEGF method qualitatively. Lattice dynamics calculations reveal that these phenomena can be attributed to the reduction of both phonon group velocities and phonon lifetimes in graphyne at low-frequency region. However, when the temperature is less than 30 K, the thermal conductance of graphyne exceeds that of graphene. Moreover, the anomalous thermal conductance behavior is not sensitive to the system lateral size. The underlying mechanisms for such phenomena are elaborated by the normal mode analysis.

Transplantation and perfusion of microvascular fragments in a rodent model of volumetric muscle loss injury

Few clinical options are available for the treatment of volumetric muscle loss (VML). An important consideration that needs to be addressed for the development of treatments for these injuries is the establishment of a vascular supply sufficient to support skeletal muscle regeneration. The objective of the current study was to evaluate the potential for microvascular fragments (MVFs) harvested from adipose tissue to support tissue perfusion for VML. Tibialis anterior muscle defects in rats were replaced with constructs that were created on the day of surgery containing either (1) collagen only (COL), (2) freshly isolated microvascular fragments in collagen (MVF), or (3) adipose tissue derived stem cells (ASCs) in collagen. Muscles were harvested 7 and 14 days after surgery. Defects treated with MVFs had a vessel density higher than the other groups at both 7 and 14 days, and those treated with ASCs had a higher vessel density than COL by day 14 (p < 0.05). Perfused vessels were observed in both the ASC and MVF treated defects at day 14, as well as at day 7 in the MVF. This study supports the use of MVFs as a platform to improve tissue perfusion to treat large VML defects. The use of freshly isolated MVFs on the day of surgery supports their clinical use and application.

Nano-polycrystalline vanadium oxide thin films prepared by pulsed laser deposition

Nano-polycrystalline vanadium oxide thin films have been successfully produced by pulsed laser deposition on Si(100) substrates using a pure vanadium target in an oxygen atmosphere. The vanadium oxide thin film is amorphous when deposited at relatively low substrate temperature (500 degrees C) and enhancing substrate temperature (600-800 degrees C) appears to be efficient in crystallizing VOx thin films. Nano-polycrystalline V3O7 thin film has been achieved when deposited at oxygen pressure of 8 Pa and substrate temperature of 600 degrees C. Nano-polycrystalline VO2 thin films with a preferred (011) orientation have been obtained when deposited at oxygen pressure of 0.8 Pa and substrate temperatures of 600-800 degrees C. The vanadium oxide thin films deposited at high oxygen pressure (8 Pa) reveal a mix-valence of V5+ and V4+, while the VOx thin films deposited at low oxygen pressure (0.8 Pa) display a valence of V4+. The nano-polycrystalline vanadium oxide thin films prepared by pulsed laser deposition have smooth surface with high qualities of mean crystallite size ranging from 30 to 230 nm and Ra ranging from 1.5 to 22.2 nm. Relative low substrate temperature and oxygen pressure are benifit to aquire nano-polycrystalline VOx thin films with small grain size and low surface roughness.

Quantification of brain creatine concentration using PRESS sequence and LCModel: comparison with HPLC method

To investigate the accuracy for quantification of brain total creatine (Cr) concentration using in vivo long echo time (TE) PRESS sequence with an external standard and LCModel. Ten swine and an external standard containing a detectable compounds of known concentration were studied by using 1.5 T GE Signa scanner and the standard head coil; the single-voxel proton magnetic resonance spectroscopy (1H-MRS) data was acquired from the 20-mm cubic VOI which was placed in the swine brain and external standard respectively by using the PRESS sequence with TE=135 msec, TR=1500 msec, and 128 scan averages. The quantification of Cr was accomplished by the linear combination of model spectra (LCModel). After MRS examination, each animal was sacrificed, and in vitro Cr concentration was analyzed by high performance liquid chromatography (HPLC). In the MRS group, the mean concentration of Cr was 9.37+/-0.137mmol/kg; in the HPLC group, the mean concentration of Cr was 8.905+/-0.126 mmol/kg. There were no statistically significant differences between two methods (P=0.491), which indicated that long TE PRESS sequence with an external standard can accurately detect the brain Cr concentration. The application of LCModel introduces more convenience for the MRS quantification.

Functional magnetic resonance mapping of motor cortex in patients with mass lesions near primary motor and sensory cortices

PURPOSE

To study motor cortex mapping in patients with mass lesions near primary motor and sensory cortices with BOLD-fMRI.

MATERIAL AND METHODS

18 patients with mass lesions near primary motor and sensory cortices, and 8 healthy volunteers were investigated with fMRI using a 1.5 T GE Signa scanner. The specific task was repetitive selfpaced index finger to thumb opposition with a frequency of approximately 2 Hz. Each task paradigm consisted of twelve 20-second blocks alternating between rest and activation. All functional data was sent to SUN GE Advanced Workstation 4.0 for post processing.

RESULTS

14 patients showed functional activation near mass lesion, 4 patients failed to show, and one patient with meningeoma was excluded because of heavy head movement. Of 14 patients, the functional activation of eloquent cortex was different between the group with declination of muscle force and the group with normal muscle force, generally the activated areas of the former were more scattered, dislocated, relative smaller than that of the latter.

CONCLUSION

fMRI is a valuable method for pre-operative evaluation of neurosurgical patients and probably can evaluate the muscle force pre- and post-operation approximately.

Pregnancy-induced hypertension and infant mortality in triplets

OBJECTIVE

To assess the effects of pregnancy-induced hypertension on infant mortality in triplets stratified by gestational age at birth.

METHODS

A retrospective cohort study was conducted using the linked 1995-2000 US birth/infant death database. Generalized estimating equations were used to evaluate the observed association.

RESULTS

Pregnancy-induced hypertension was associated with lesser neonatal mortality (odds ration [OR]: 0.34, 95% CI: 0.21, 0.54), postneonatal mortality (OR: 0.54, 95% CI: 0.30, 0.99) and infant mortality (OR, 0.37, 95% CI: 0.25, 0.55) in triplets. It was also associated with a decreased risk of neonatal death (OR, 0.38; 95% CI, 0.21-0.67), postneonatal death (OR, 0.45; 95% CI, 0.21-0.97), and infant death (OR, 0.39; 95% CI, 0.24-0.64) in early preterm triplets, whereas the association was not significant in late preterm or in full-term triplets.

CONCLUSION

Pregnancy-induced hypertension is associated with a decreased risk of infant mortality in triplets. This effect varies with gestational age at birth.

Association of caesarean delivery for first birth with placenta praevia and placental abruption in second pregnancy

OBJECTIVE

To quantify the risk of placenta praevia and placental abruption in singleton, second pregnancies after a caesarean delivery of the first pregnancy.

DESIGN

Retrospective cohort study.

SETTING

Linked birth and infant mortality database of the USA between 1995 and 2000.

POPULATION

A total of 5,146,742 singleton second pregnancies were available for the final analysis after excluding missing information.

METHODS

Multiple logistic regressions were used to describe the relationship between caesarean section at first birth and placenta praevia and placental abruption in second-birth singletons.

MAIN OUTCOME MEASURES

Placenta praevia and placental abruption.

RESULTS

Placenta praevia was recorded in 4.4 per 1000 second-birth singletons whose first births delivered by caesarean section and 2.7 per 1000 second-birth singletons whose first births delivered vaginally. About 6.8 per 1000 births were complicated with placental abruption in second-birth singletons whose first births delivered by caesarean section and 4.8 per 1000 birth in second-birth singletons whose first births delivered vaginally. The adjusted odds ratio (95% CIs) of previous caesarean section for placenta praevia in following second pregnancies was 1.47 (1.41, 1.52) after controlling for maternal age, race, education, marital status, maternal drinking and smoking during pregnancy, adequacy of prenatal care, and fetal gender. The corresponding figure for placental abruption was 1.40 (1.36, 1.45).

CONCLUSION

Caesarean section for first live birth is associated with a 47% increased risk of placenta praevia and 40% increased risk of placental abruption in second pregnancy with a singleton.

Paternal age and birth defects: how strong is the association?

BACKGROUND

Although the association between maternal age and the risks of birth defects has been well studied, the evidence from population data linking paternal age with birth defects was limited and inconsistent.

METHODS

We conducted a population-based retrospective cohort study of 5,213,248 subjects from the 1999-2000 birth registration data of the USA. Multiple logistic regressions were used to estimate the independent effect of paternal age on all birth defects and 21 specific defects groups after adjusting for potential confounding of maternal age, race, education, marital status, parity, prenatal care initiation, maternal smoking and alcohol drinking during pregnancy.

RESULTS

A total of 77,514 (1.5%) birth defects were recorded in the study cohort. The adjusted odds ratios were 1.04 (1.01, 1.06), 1.08 (1.04, 1.12), 1.08 (1.02, 1.14) and 1.15 (1.06, 1.24), respectively, for infants born to fathers 30-35, 40-44, 45-49 and over 50 years (test for trend, P = 0.0155), when compared with those infants born to fathers aged 25-29 for any birth defect. Advanced paternal age was associated with increased risks of heart defects, tracheo-oesophageal fistulaoesophageal atresia, other musculoskeletal/integumental anomalies, Down's syndrome and other chromosomal anomalies. Fathers under 25 years of age were also at increased risks of spina bifida/meningocele, microcephalus, omphalocele/gastroschisis and other musculoskeletal/integumental anomalies.

CONCLUSIONS

Infants born to older fathers have a slightly increased risk of birth defects. Young paternal age is also associated with slightly increased risk of several selected birth defects in their offspring. However, given the weak association, paternal age appears to play a small role in the aetiology of birth defects.

Pregnancy-induced hypertension and infant mortality: roles of birthweight centiles and gestational age

OBJECTIVE

To assess the effect of pregnancy-induced hypertension (PIH) on infant mortality in different birthweight centiles (small for gestational age [SGA], appropriate for gestational age [AGA], and large for gestational age [LGA]) and gestational ages (early preterm, late preterm, and full term).

DESIGN

Retrospective cohort study.

SETTING

Linked birth and infant death data set of USA between 1995 and 2000.

POPULATION

A total of 17 464 560 eligible liveborn singleton births delivered after 20th gestational week.

METHODS

Multivariate logistic regression models were applied to evaluate the association between PIH and infant mortality, with adjustment of potential confounders stratified by birthweight centiles and gestational age.

MAIN OUTCOME MEASURE

Infant death (0-364 days) and its three components: early neonatal death (0-6 days), late neonatal death (7-27 days), and postneonatal death (28-364 days).

RESULTS

PIH was associated with decreased risks of infant mortality, early neonatal mortality, and late neonatal mortality in both preterm and term SGA births, and PIH was associated with lower postneonatal mortality in preterm SGA births. PIH was associated with decreased risks of infant mortality, early neonatal mortality, late neonatal mortality and postneonatal mortality in preterm AGA births. Decreased risk of infant mortality and early neonatal mortality was associated with PIH in early preterm LGA births.

CONCLUSIONS

The association between PIH and infant mortality varies depending on different birthweight centiles, gestational age, and age at death. PIH is associated with a decreased risk of infant mortality in SGA births, preterm AGA births, and early preterm LGA births.

Changes in nuclei and peritumoral collagen within nodular basal cell carcinomas via confocal micro-Raman spectroscopy

Confocal micro-Raman spectroscopy is used to probe the nuclei of normal human epidermal cells and epidermally derived cancer cells from nodular basal cell carcinomas. Clear differences are seen between the spectra. The nuclei of tumor cells appear to have different contributions from nucleic acids, histones, and proteins with an actin-like spectrum than those of normal epidermal cells. Changes in the contribution of DNA to the spectra are consistent with the staining of conventional histopathologic specimens. We also obtain spectra of the dermis, where it is found that the dermis close to tumor boundaries is not simply deficient in collagen, but shows signs of structural changes as well.

Pregnancy-induced hypertension is associated with lower infant mortality in preterm singletons

OBJECTIVE

To assess the association between pregnancy-induced hypertension (PIH) and infant mortality.

DESIGN

Retrospective cohort study.

SETTING

Birth and infant death registration dataset of the USA.

POPULATION

A total of 17,432,987 eligible, liveborn singleton births in 1995-2000.

METHODS

Multivariate logistic regression was applied to evaluate the association between PIH and infant mortality, with adjustment of potential confounders.

MAIN OUTCOME MEASURES

Infant death (0-364 days) and its three components: early neonatal death (0-6 days), late neonatal death (7-27 days), and postneonatal death (28-364 days).

RESULTS

There was a significant reduction in infant mortality associated with PIH in early preterm infants (OR = 0.59, 95% CI: 0.56-0.63) and in late preterm infants (OR = 0.80, 95% CI: 0.73-0.87), but a significant increase in term infants (OR = 1.08, 95% CI: 1.02-1.14). Both in early preterm and late preterm births, early neonatal mortality (OR = 0.38, 95% CI: 0.34-0.42; OR = 0.68, 95% CI: 0.61-0.77) and late neonatal mortality (OR = 0.59, 95% CI: 0.50-0.70; OR = 0.76, 95% CI: 0.61-0.96) were decreased in infants born to mothers with PIH compared with those born to mothers with normal blood pressure. The PIH-associated reduction in neonatal mortality among preterm singletons was stronger in small-for-gestational-age infants than in normal growth infants and stronger in infants born to nulliparous women than in those born to multiparous women.

CONCLUSIONS

PIH is associated with lower risk of infant death in preterm births but higher risk in term births.

The brain mapping on reinforcement acupuncture stimulation at ST36 (zusanli) evidenced by fMRI

To characterize the brain mapping on reinforcement acupuncture stimulation at ST36 (zusanli), and to discuss the mechanisms of acupuncture to treat diseases. fMRI was performed on 26 healthy Chinese student volunteers. Sixteen subjects were acupunctured at the acupoint ST36, while 10 others at sham-acupoint (lateral from ST36 about 3 cm). The fMRI studies were performed using a gradient echo-EPI sequence. Brain mapping were generated using GE Functool program. Cerebral blood flow and correlation coefficient (CC) of ROl were analyzed. Stimulation at the right ST36 elicited 13 brain functional areas, and 10 of these areas were the same with the sham-acupoint group. However, only the temporal gyrus was specificity while by using reinforcement manual acupuncture (MA) at ST36 (Fisher's Exact test, P=0.022), and the contralateral hemisphere activation was prominent (McNemer test, P=0.020). Our results support the theory of acupuncture about meridian distribution overlapping on the whole body. The special transmission channel of meridian may exists, and it may be consist of spinal nerve and autonomic nerve. However, our results may oppose the theory concerning on stomach meridian walking lateral.

Raman spectroscopy of in vivo cutaneous melanin

We successfully acquire the in vivo Raman spectrum of melanin from human skin using a rapid near-infrared (NIR) Raman spectrometer. The Raman signals of in vivo cutaneous melanin are similar to those observed from natural and synthetic eumelanins. The melanin Raman spectrum is dominated by two intense and broad peaks at about 1580 and 1380 cm(-1), which can be interpreted as originating from the in-plane stretching of the aromatic rings and the linear stretching of the C-C bonds within the rings, along with some contributions from the C-H vibrations in the methyl and methylene groups. Variations in the peak frequencies and bandwidths of these two Raman signals due to differing biological environments have been observed in melanin from different sources. The ability to acquire these unique in vivo melanin signals suggests that Raman spectroscopy may be a useful clinical method for noninvasive in situ analysis and diagnosis of the skin.

Evidence for two superconducting gaps in MgB2

We have measured the Raman spectra of polycrystalline MgB2 from 25 to 1200 cm(-1). A superconductivity-induced redistribution in the electronic Raman continuum was observed. Two pair-breaking peaks appear in the spectra, suggesting the presence of two superconducting gaps. The measured spectra were analyzed using a quasi-two-dimensional model in which two s-wave superconducting gaps open on two sheets of Fermi surface. For the gap values we have obtained Delta(1) = 22 cm(-1) ( 2.7 meV) and Delta(2) = 50 cm(-1) ( 6.2 meV). Our results suggest that a conventional phonon-mediated pairing mechanism occurs in the planar boron sigma bands and is responsible for the superconductivity of MgB2.

[The diploid of genetically engineered yeast for expression of hybrid HBsAg gene SA-28]

By mating a yeast haploid expressing hybrid HBsAg gene SA-28, Y19/YFD158, with another hapolid Y95, the diploid Y95xY19/YFD158 was constructed. The experiments showed that the cell density of the diploid in fermentation was three time higher than that of the haploid, the stability of expression vector in the diploid was much higher than in the haploid, the xpression level of hybrid HBsAg gene of the diploid was more than three time higher than that of the haploid and the average cope number in diploid cell was a little lower than that in the haploid.

[Isolation and identification of two new saponins from Bupleurum smithii Wolff]

Two new saikosaponins of oleanane type were isolated from the roots of Bupleurum smithii Wolff, collected in Minhe County, Qinghai, namely saikosaponin k (VIb) and saikosaponin 1 (VIII). Their structures were elucidated on the basis of spectral analysis of UV, IR, 1HNMR, 13CNMR and FAB-MS. Saikosaponin k (VIb) was identified as 3 beta, 16 beta, 23,28-tetrahydroxyoleana-11,13(18)-dien-3-O-beta-D-xylopyranosyl-(1-->2)-beta- D-glucopyranosyl-(1-->3)-beta-D-fucopyranoside, and saikosaponin 1 (VIII) as 3 beta, 16 alpha, 23,28,30-pentahydroxyoleana-11,13(18)-dien-3-O-beta-D- glucopyranosyl-(1-->3)-beta-D-fucopyranoside, respectively.

Operative treatment of bilateral retrocollis

A surgical method for bilateral retrocollis (BR) is presented: Selective resection of specific posterior cervical muscles for the treatment of bilateral retrocollis is described. The operative procedure includes partial resection of the upper part of the trapezius, part of the splenius muscles of both sides, part of the semispinalis capitis and semispinalis cervicis muscles of both sides. 15 cases were treated surgically during 1980-1989. Postoperative follow up (3-10 years) showed that the abnormal movements were abolished completely or for the greater part in 13 patients (87%) while preserving the normal posture and mobility.