A bionic bird jumping grasping structure design based on stm32 development board control.

During takeoff and landing, birds bounce and grab with their legs and feet. In this paper,the lower limb structure of the bionic bird is designed with reference to the function of jumping and grasping, and the PID algorithm based on the development module of stm32 development board is used to speed control the lower limb driving element, so that the motor and the bishaft steering gear move with the rate change of sine wave. According to the speed of grasping response time and the size of grasping force, the structure of the bionic bird paw is designed. Based on the photosensitive sensor fixed in the geometric center of the foot, the grasping action of the lower limb mechanism is intelligently controlled. Finally, the kinematic verification of the lower limb structure is carried out by ADAMS. Experiments show that the foot structure with four toes and three toes is more conducive to maintaining the stability of the body while realizing the fast grasping function. In addition, it can effectively improve the push-lift ratio of the bionic ornithopter by adjusting the sinusoidal waveform rate of the motor speed.

Prognostic analysis of stereotactic radiosurgery for brain metastases: a single-center retrospective study.

OBJECTIVES: Brain metastasis (BM) is a common event during the development of many cancers, and is also one of the main causes of death of patients. Stereotactic radiosurgery (SRS) is an effective treatment for BM. The prognostic effects of various clinical factors on local control (LC) and overall survival (OS) after SRS treatment are still unclear. The purpose of this study is to retrospectively analyze the intracranial progression free survival (iPFS) and OS of patients receiving SRS treatment, and explore the relationship between various clinical characteristics and patient prognosis. MATERIALS AND METHODS: We collected the clinical information of patients who were diagnosed with BM and received SRS treatment in our center between 2018 and 2021. Univariate and multivariate Cox regression analysis and KM analysis for iPFS and OS were conducted in R software to investigate the prognostic effects of clinical characteristics. RESULTS: In total, 183 patients that received SRS in our center were enrolled in the cohort. The median iPFS for all patients was 8.87 months (95% CI 6.9-10.6), and the median OS was 16.5 months (95% CI 12.9-20.7). BM number > = 5 (HR 1.965 [95% CI 1.381-2.796], p < 0.001, FDR-corrected p < 0.001) was found to be strong predictor for shorter iPFS and OS. Subgroup analysis showed that patients with cumulative intracranial tumor volume (CITV) > = 2.14 cm3 and number > = 5 had shortest iPFS (P < 0.001) and OS (P = 0.007), compared with other subgroups. For patients with more than 5 BMs, SRS plus whole brain radiotherapy (WBRT) could achieve better local control, compared with SRS alone group (P = 0.0357). Peripheral blood inflammation indicators were associated with the prognosis of BM patients in univariate Cox analysis, but not in multivariate Cox analysis. CONCLUSIONS: BM number is an independent prognostic factor for BM patients. The prognosis of patients in the subgroup with larger CITV and more BM is the worst. For patients with more than 5 BM, the combination of SRS and WBRT can improve the local control, but cannot prolong the OS.

Optimization of Cu/Sn Alloy Sputtering Process Based on Orthogonal Experimental Design Method.

The performance of supercapacitors is directly influenced by the conductivity of polypyrrole, which serves as the electrode material. In order to balance considerations of cost-effectiveness and conductivity, this study employs magnetron sputtering to fabricate a copper-tin alloy layer as the conductive layer for polypyrrole. The deposition of a copper-tin alloy film through magnetron sputtering has a significant impact on the polymerization effect of pyrrole as well as being a crucial factor influencing the performance of supercapacitors. Various parameters, including working pressure, sputtering time, and sputtering power, affect the conductivity of the copper-tin alloy film. Furthermore, the degree of influence of each parameter on the conductivity of the copper-tin alloy film varies. This study utilizes an orthogonal experimental design to investigate the impact of various factors and levels on the conductivity and uniformity of a metal film. The objective is to optimize the process parameters for the creation of a copper-tin alloy film with desirable characteristics. Experimental results indicate that the working voltage, sputtering time, and sputtering power significantly influence the coefficient of variation, deposition rate, target current, and operating voltage of the film. Furthermore, FT-IR, XRD, and SEM tests are conducted on samples prepared using the identified optimal process parameters. In addition, we demonstrate various approaches to enhance the experiment's reliability. The findings indicate that the most favorable process parameters for achieving optimal results are a working pressure of 0.065 Pa, a sputtering time of 20 min, and a sputtering power of 70 W. It was observed that the sputtering time significantly influences the uniformity of the copper-tin alloy film, whereas the sputtering power has a minimal impact on its uniformity. The deposition rate is primarily influenced by the working pressure, with the greatest effect observed. Conversely, the sputtering time has the least impact on the deposition rate. Similarly, the target current is predominantly affected by the sputtering power, exhibiting the greatest influence, while the sputtering time has the least effect. Furthermore, the working voltage is most significantly influenced by the working pressure, whereas the sputtering time has the least impact on the working voltage.

Structure Design and Characterization of 3D Printing System of Thermal Battery Electrode Ink Film.

In this paper, a 3D printing system for a thermal battery electrode ink film is set up and investigated based on the on-demand microdroplet ejection technology. The optimal structural dimensions of the spray chamber and metal membrane of the micronozzle are determined via simulation analysis. The workflow and functional requirements of the printing system are set up. The printing system includes a pretreatment system, piezoelectric micronozzle, motion control system, piezoelectric drive system, sealing system, and liquid conveying system. Different printing parameters are compared to obtain optimized printing parameters, which can be attributed to the optimal pattern of the film. The feasibility and controllability of 3D printing methods are verified by printing tests. The size and output speed of the droplets can be controlled by adjusting the amplitude and frequency of the driving waveform acting on the piezoelectric actuator. So, the required shape and thickness of the film can be achieved. An ink film in terms of nozzle diameter = 0.6 mm, printing height = 8 mm, wiring width = 1 mm, input voltage = 3 V and square wave signal frequency = 35 Hz can be achieved. The electrochemical performance of thin-film electrodes is crucial in thermal batteries. The voltage of the thermal battery reaches its peak and tends to flatten out at around 100 s when using this printed film. The electrical performance of the thermal batteries using the printed thin films is found to be stable. This stabilized voltage makes it applicable to thermal batteries.

Prediction of distant organ metastasis and overall survival of lung cancer patients: a SEER population-based cohort study.

Background: Distant organ metastasis is a common event in lung cancer (LC). However, the preferential metastatic pattern of different pathological types of LC and its effect on prognosis have not been comprehensively elucidated. This study aimed to explore the distant metastasis pattern and construct nomograms predicting the metastasis and survival of LC patients using the Surveillance, Epidemiology, and End Results (SEER) database. Methods: LC data were downloaded from the SEER database to conduct logistic regression and investigate risk factors for developing organ metastasis. A Cox regression analysis was conducted to investigate prognostic factors of LC. A Kaplan-Meier analysis was used to estimate overall survival outcomes. Nomograms were constructed to predict the probability of organ metastasis and the 1-, 3- and 5-year survival probability of LC patients. Receiver operating characteristic curves were used to evaluate the diagnostic accuracy of the nomograms. All statistical analyses were conducted within R software. Results: The liver is the most common metastatic organ of small cell carcinoma. The brain is the most likely metastasis site of large cell carcinoma, and bone is the most likely metastasis site for squamous cell carcinoma and adenocarcinoma. Patients with triple metastases (brain-bone-liver) have the worst prognosis, and for nonsquamous carcinoma with single organ metastasis, liver metastases conferred the worst prognosis. Our nomograms based on clinical factors could predict the metastasis and prognosis of LC patients. Conclusion: Different pathological types of LC have different preferential metastatic sites. Our nomograms showed good performance in predicting distant metastasis and overall survival. These results will provide a reference for clinicians and contribute to clinical evaluations and individualized therapeutic strategies.

Risk and prognostic factors of brain metastasis in lung cancer patients: a Surveillance, Epidemiology, and End Results population­based cohort study.

BACKGROUND: Brain is a common metastasis site in lung cancer patients. However, homogeneous and heterogeneous risk/prognostic factors of brain metastasis for lung cancer patients have not been comprehensively elucidated. This study aimed to explore the brain metastasis risk and prognostic factors in lung cancer patients using the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: Lung cancer data were downloaded from SEER database to investigate risk factors for developing brain metastasis using logistic regression analysis. Univariate and multivariate Cox analyses were used to identify potential prognostic factors. Kaplan-Meier analysis was conducted to evaluate the survival. Propensity score matching was conducted to eliminate baseline differences between two groups. RESULTS: A total of 10 818 (14.1%) patients with brain metastasis were diagnosed among 76 483 lung cancer patients. For non-small-cell lung carcinoma (NSCLC), distant liver/bone/lymph node metastases, higher T, N stages were risk factors. Black race, bone metastases and distant lymph node metastases and T4 were brain metastasis risk factors for SCLC patients. Cox analysis suggested that older age, male, primary lesion at main bronchus, liver/ bone/distant lymph node metastases, T2-4, N1-3, no surgery/chemotherapy/radiotherapy were associated with worse prognosis of NSCLC-brain metastasis patients. Age older than 80, liver/bone metastases, without radiotherapy and chemotherapy were associated with worse prognosis of SCLC-brain metastasis patients. Surgery of primary site could prolong the overall survival (OS) of NSCLC patients with brain metastasis, but not SCLC. CONCLUSION: In this study, we analyzed the homogeneous and heterogeneous risk/prognostic factors of brain metastasis in lung cancer patients. What is more, our results showed that surgery of primary site was associated with longer OS of NSCLC patients with brain metastasis.

Research on Attitude Detection and Flight Experiment of Coaxial Twin-Rotor UAV.

Aiming at the problem that the single sensor of the coaxial UAV cannot accurately measure attitude information, a pose estimation algorithm based on unscented Kalman filter information fusion is proposed. The kinematics and dynamics characteristics of coaxial folding twin-rotor UAV are studied, and a mathematical model is established. The common attitude estimation methods are analyzed, and the extended Kalman filter algorithm and unscented Kalman filter algorithm are established. In order to complete the test of the prototype of a small coaxial twin-rotor UAV, a test platform for the dynamic performance and attitude angle of the semi-physical flight of the UAV was established. The platform can analyze the mechanical vibration, attitude angle and noise of the aircraft. It can also test and analyze the characteristics of the mechanical vibration and noise produced by the UAV at different rotor speeds. Furthermore, the static and time-varying trends of the pitch angle and yaw angle of the Kalman filter attitude estimation algorithm is further analyzed through static and dynamic experiments. The analysis results show that the attitude estimation of the UKF is better than that of the EKF when the throttle is between 0.2σ and 0.9σ. The error of the algorithm is less than 0.6°. The experiment and analysis provide a reference for the optimization of the control parameters and flight control strategy of the coaxial folding dual-rotor aircraft.

Simulation and Test of a MEMS Arming Device for a Fuze.

To solve the structural strength problem of a MEMS arming device for a fuze, a kind of arming device applied to a certain type of 40 mm grenade is designed. This paper introduces the working principle of the arming device; simulates the shear pin, rotary pin and locking mechanism in the device; designs a variety of different test tools for test verification; and further increases the explosion reliability and arming safety tests. The results show that the arming device improves the structural strength and can meet the action requirements of a certain type of 40 mm grenade for safety release, as well as the application requirements of explosion reliability and arming safety.

Test and Improvement of a Fuze MEMS Setback Arming Device Based on the EDM Process.

This paper introduces the working principle of a MEMS safety and arming (S&A) device for a fuze that is installed perpendicular to the axis of the projectile. Additionally, the application of low-speed wire electrical discharge machining (EDM) in the fabrication of the device is proposed. Microsprings are susceptible to flexural deformation and secondary deformation in the EDM process, a problem that is solved by designing the auxiliary support beam, using multiple cuts, destress annealing and optimizing the processing parameters. The difficult problem of setback slider deformation in the principle prototype test is properly solved by establishing V-shaped grooves at both ends of the setback slider. The connection mode between the microspring and the frame is changed to a clearance fit connection. The improved setback arming device can guarantee service process safety and launch reliability. The maximum overload that can be withstood in service processing is 20,000 g, and the minimum overload for safety release during launch is 12,000 g. The results show that the EDM process can greatly reduce the machining cost while improving the machining precision and machining speed, which can compensate for the defects of the current manufacturing technology.

EFNA1 is a potential key gene that correlates with immune infiltration in low-grade glioma.

ABSTRACT: EFNA1 is a key gene that is associated with the pathogenesis of several human cancers. However, the prognostic role of EFNA1 in many cancers and the relationship between EFNA1 and tumor-infiltrating lymphocytes in different cancers remain unclear.The expression levels of EFNA1 in 33 types of cancer in the TCGA (The Cancer Genome Atlas) database were collected via the UCSC Xena browser. The clinical data of LGG (low grade glioma) patients were downloaded from the TCGA database. The glioma data from the CGGA (Chinese Glioma Genome Atlas) database were also downloaded to verify the results. Kaplan-Meier and Cox regression analyses were used to investigate the prognostic value of EFNA1 in different cancers using R software. We verified the differential expression of EFNA1 in glioma and normal brain tissue via gene expression profiling interactive analysis. We evaluated the relationship between the expression level of EFNA1 and the clinicopathological features of LGG patients via the Wilcoxon signed-rank test. The immune infiltration levels were evaluated via tumor immune estimation resource (TIMER) and CIBERSORT, and the correlations between EFNA1 and immune cell levels were investigated via TIMER. Finally, we conducted gene set enrichment analysis (GSEA) to explore the potential mechanisms.Data from the TCGA database showed that EFNA1 was differentially expressed in many kinds of cancers when compared with normal tissues. Upregulated EFNA1 expression in esophageal carcinoma (ESCA), cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), and LGG correlated with shorter patient overall survival (OS) times. The Cox regression analysis revealed that the expression of EFNA1 was also a risk factor for the disease-specific survival (DSS) and progression-free interval (PFI) of LGG patients. The multiple Cox regression analysis revealed that EFNA1 was an independent prognostic factor for LGG patients. In addition, EFNA1 expression was increased in the WHO grade III group and the 1p19q non-codeletion group. Moreover, EFNA1 expression was positively correlated with the levels of infiltrating CD4+ T cells, myeloid dendritic cells and neutrophils in LGG. GSEA suggested that several GO and kyoto encyclopedia of genes and genomes (KEGG) items associated with nervous system function and apoptotic pathway were significantly enriched in the EFNA1-low and EFNA1-high expression phenotypes.EFNA1 may play a pivotal role in the development of LGG and may serve as a potential marker for LGG prognosis and therapy.

Theoretical prediction of the trigger linkage, cage strain, and explosive sensitivity of CL-20 in the external electric fields.

In order to add safely external electric fields into the systems of the explosives with strong cage strain, the effects of the external electric fields on the strengths of trigger linkages, cage strain energies (CSEs), surface electrostatic potentials (ESPs), as well as impact and shock initiation sensitivities of CL-20 were investigated using the B3LYP and M06-2X methods with 6-311++G(2d,p) basis set. The results show that the changes of the strengths of the N-NO2 bonds are more notable than those of the bonds forming cage, and the changes involving the N-NO2 bonds attached to the five-membered ring are more significant than those attached to the six-membered ring. In most cases, the CSEs in the electric fields are stronger than those in no field. From the BDEs, the N-NO2 cleavage is the decomposition reaction pathway in detonation initiation. However, from the surface ESPs, the N-NO2 cleavage, C-N and C-C bond breaking may initiate the reactions. The global ESPs are more reasonable and reliable to estimate the impact sensitivities of the cage-shaped explosives. The changes of the bond lengths, Mulliken bond orders, nitro group charges and BDEs correlate well with the external electric field strengths. Interestingly, an abnormal result is found that the h50 values in the electric fields are larger than those in no field.

Role of EFNA1 in tumorigenesis and prospects for cancer therapy.

Cancer is one of the major threats to human health. It is of vital importance to reveal the mechanisms of tumorigenesis, identify effective biomarkers and develop novel treatments to improve patient outcome. EFNA1 (ephrinA1) is a member of the EFN family, and it has been studied extensively since its discovery in 1990. Increasing evidence indicates that EFNA1 plays a pivotal role in the pathogenesis of tumors. We provide a detailed overview of the expression and prognostic value of EFNA1 in different types of human malignancies. We briefly discuss the mechanisms of EFNA1 induction in hypoxic environments and its pro-angiogenic function in different cancer cells. We describe the effects of EFNA1 on tumor growth, invasiveness and metastasis. We summarize recent advances in EFNA1-associated cancer therapeutics with emphasis on the prospect of novel anti-tumor methods based on EFNA1.

Calibration Technique of a Curved Zoom Compound Eye Imaging System.

A calibration method for the designed curved zoom compound eye is studied in order to achieve detection and positioning of spatial objects. The structure of the curved zoom compound eye is introduced. A calibration test platform is designed and built based on the image characteristics of the compound eye, which can be constructed in the large field view for the calibration target. The spot images are obtained through image processing. The center of the spot is calculated by Gauss fitting method. This method is highly simple and intuitive, and it can be used in a zoom surface compound eye without any complex procedures. Finally, the corresponding relationship between the spot center coordinates and the incident light vector of the corresponding sub-eye is established, and the calibration of the multi vision positioning system is completed.

Fabrication and Characterization of Inhomogeneous Curved Artificial Compound Eye.

Compared with the conventional compound eye processing method, a new fabrication method-namely, a mold casting method-was presented. This method is simple, low-cost, easy to implement, and can be reused. A bionic compound eye array model with 61 ommatidia arranged inhomogeneously onto a curved surface was fabricated. The curved surface had a radius of 9 mm and a thickness of 0.5 mm. The margin imaging quality was improved significantly by the analysis of light beam focus and the optical imaging properties of the fabricated compound eye. The sub-image of each ommatidium had a high resolution. There was 5% error between the collecting spot brightness and simulation analysis results, which proved that the production method is feasible.

The Design and Positioning Method of a Flexible Zoom Artificial Compound Eye.

The focal lengths of the sub-eyes in a single-layer uniform curved compound eye are all the same, resulting in poor imaging quality for the compound eye. A non-uniform curved compound eye can effectively solve the problem of poor edge-imaging quality, however, it suffers from a large spherical aberration, and is unable to achieve zoom imaging. To solve these problems, a new type of aspherical artificial compound eye structure with variable focal length is proposed in this paper. The structure divides the surface compound eye into three fan-shaped areas with different focal lengths of the microlens in different areas, which allow the artificial compound eye to zoom in a certain range. The focal length and size of the microlens is determined by the area and the location of the microlens. The aspherical optimization of the microlens is calculated, and spherical aberration in each area is reduced to one percent of the initial value. Through simulation analysis, the designed artificial compound eye structure realizes focal length adjustment and effectively reduces the problem of the poor imaging quality of the curved compound eye edge. As a result, an aspherical artificial compound eye sample-where the number of sub-eyes is n = 61, and the diameter of the base is Φ = 8.66 mm-was prepared by using a molding method. Additionally, the mutual relationship between the eyes of the child was calibrated, and hence, a mathematical model for the simultaneous identification of multiple sub-eyes was established. This study set up an experimental artificial compound eye positioning system, and through a number of microlens capture target point settlement coordinates, achieved an error value of less than 10%.

Systematic review and meta-analysis of pertussis epidemiology in Latin America and the Caribbean: 1980–2015 / Examen sistemático y metanálisis de las características epidemiológicas de la tos ferina en América Latina y el Caribe: 1980-2015 / Revisão sistemática e metanálise da epidemiologia da coqueluche na América Latina e Caribe: 1980 a 2015

[English]. Objectives. In Latin America and the Caribbean (LAC), pertussis disease incidence has reportedly increased since 2000 despite high vaccine coverage. A systematic review of pertussis literature and a meta-analysis was conducted to understand the burden of disease in LAC. Methods. A systematic literature review was completed, using relevant search terms. Original articles describing pertussis epidemiology and vaccine coverage in LAC published between 1980 and 2015 were identified. Applying a Bayesian meta-analysis random-effects model, we calculated pooled estimates and corresponding 95% credible intervals (95% CrIs) for pertussis incidence, case fatality ratio (CFR), pertussis prevalence among contacts, and coverage with three doses of diphtheria, tetanus, and pertussis (DTP) vaccine (DTP3). Results. A total of 59 studies meeting our selection criteria were identified, representing 15 countries. Of the 59, 15 of them provided incidence data, with 7 of the 15 reporting a pertussis case definition. The pertussis incidence estimate for the 1980–1999 period was 17.8 cases per 100 000 persons (95% CrI: 5.9–29.7); for the 2000–2015 period, it was 2.5 cases per 100 000 persons (95% CrI: 1.8–3.2). For the 1980–2015 period, the CFR, in 19 studies reviewed, was 3.9% (95% CrI: 2.9%–4.9%); for that same period, in 5 studies reviewed, pertussis prevalence among contacts was 24.9% (95% CrI: 13.7%–36.1%). Pooled DTP3 vaccine coverage estimates, in a total of 20 studies reviewed for the following three time periods, were: 1980–1990, 72.4% (95% CrI: 64.6%–80.2%); 1991–2000, 79.0% (95% CrI: 66.1%–91.9%); and 2001–2015, 90.0% (95% CrI: 87.7%–92.3%). Conclusion. A decrease in pertussis incidence and an achievement of moderately high DTP3 vaccine coverage since the early 2000s was observed. The review highlights the need for increased publication of pertussis data at the country level and for LAC as a whole in order to better understand the true burden of the disease. Application of a standardized case definition and use of active case finding would aid in obtaining more accurate estimates of the disease burden in LAC.

[Español]. Objetivos. En América Latina y el Caribe, la incidencia de la tos ferina habría aparentemente aumentado desde el 2000, a pesar de la alta cobertura de vacunación. Se realizó una revisión sistemática de la bibliografía sobre tos ferina y un metanálisis para conocer la carga de esta enfermedad en América Latina y el Caribe. Métodos. La revisión bibliográfica sistemática se realizó utilizando términos de búsqueda pertinentes. Se encontraron artículos originales que describían las características epidemiológicas de la tos ferina y la cobertura de vacunación en América Latina y el Caribe publicados entre 1980 y el 2015. Aplicando un modelo bayesiano de efectos aleatorios para el metanálisis, se obtuvieron estimaciones combinadas y los correspondientes intervalos de credibilidad del 95% (ICr) para la incidencia, la tasa de letalidad y la prevalencia entre contactos de la tos ferina, y la cobertura con tres dosis de vacuna contra la difteria, el tétanos y la tos ferina (DTP3). Resultados. Se encontraron en total 59 estudios de 15 países que cumplían con los criterios de selección. De ellos, 15 proporcionaban datos sobre incidencia. Siete de estos 15 contenían una definición de caso de tos ferina. La incidencia estimada de tos ferina para el período 1980-1999 fue de 17,8 casos por 100 000 (ICr 95%: 5,9-29,7) y para el período 2000-2015, de 2,5 casos por 100 000 (ICr 95%: 1,8-3,2). En cuanto a la tasa de letalidad, para el período 1980-2015 en 19 estudios examinados fue de 3,9% (ICr 95%: 2,9%-4,9%); en el mismo período, en 5 estudios examinados la prevalencia de tos ferina entre los contactos fue de 24,9% (ICr 95%: 13,7%-36,1%). Las estimaciones combinadas de cobertura con DTP3 en un total de 21 estudios examinados para los siguientes tres períodos fueron: en 1980-1990, 72,4% (ICr 95%: 64,6%-80,2%); en 1991-2000, 79,0% (ICr 95%: 66,1%-91,9%) y en el 2001-2015, 90,0% (ICr 95%: 87,7%-92,3%). Conclusiones. Se observó una disminución de la incidencia de la tos ferina y el logro de una cobertura moderadamente alta con la vacuna DTP3 desde principios del siglo XXI. En el examen se subraya la necesidad de incrementar la publicación de datos sobre la tos ferina en los países y en América Latina y el Caribe en su conjunto, para conocer mejor la verdadera carga de enfermedad. La adopción de una definición de caso normalizada y la búsqueda activa de casos ayudarán a obtener estimaciones más precisas de la carga de enfermedad en América Latina y el Caribe.

[Português]. Objetivos. Há relatos de que a incidência de coqueluche na América Latina e Caribe (ALC) tem aumentado desde o ano 2000, apesar da alta cobertura vacinal. Realizamos uma revisão sistemática e metanálise da literatura sobre a coqueluche para compreender a carga da doença na ALC. Métodos. Fizemos uma revisão sistemática da literatura usando termos de pesquisa relevantes. Identificamos artigos originais, publicados entre 1980 e 2015, que descrevessem a epidemiologia da coqueluche e a cobertura vacinal na ALC. Aplicando um modelo Bayesiano de efeitos aleatórios para a metanálise, calculamos estimativas agrupadas e seus correspondentes intervalos de credibilidade de 95% (CrIs 95%) para a incidência de coqueluche, a taxa de letalidade, a prevalência de coqueluche entre os contatos e a cobertura com três doses da vacina combinada para difteria, tétano e coqueluche (DTP3). Resultados. Identificamos um total de 59 estudos que cumpriram os nossos critérios de seleção, representando 15 países. Destes 59, 15 apresentaram dados sobre a incidência, e 7 dos 15 apresentaram uma definição de “caso de coqueluche”. A incidência estimada da coqueluche no período de 1980 a 1999 foi de 17,8 casos por 100.000 pessoas (CrI 95%: 5,9-29,7); no período de 2000 a 2015, foi de 2,5 casos por 100.000 pessoas (CrI 95%: 1,8-3,2). No período de 1980 a 2015, a taxa de letalidade, em 19 estudos revistos, foi de 3,9% (CrI 95%: 2,9%-4,9%); neste mesmo período, em 5 estudos revistos, a prevalência de coqueluche entre os contatos foi de 24,9% (CrI 95%: 13,7%-36,1%). A cobertura vacinal agrupada com DTP3, em um total de 21 estudos examinados nos seguintes três períodos, foi estimada em: 1980 a 1990, 72,4% (CrI 95%: 64,6%-80,2%); 1991 a 2000, 79,0% (CrI 95%: 66,1%-91,9%); 2001 a 2015, 90,0% (CrI 95%: 87,7%-92,3%). Conclusões. Foi observada uma redução na incidência de coqueluche e uma cobertura vacinal com DTP3 relativamente alta desde o início da década de 2000. Esta revisão destaca a necessidade de melhorar a publicação de dados sobre a coqueluche ao nível nacional e na ALC como um todo, a fim de promover uma melhor compreensão sobre a verdadeira carga da doença. O uso de uma definição padronizada de “caso de coqueluche” e a busca ativa de casos ajudaria na obtenção de estimativas mais precisas da carga da doença na ALC.

Systematic review and meta-analysis of pertussis epidemiology in Latin America and the Caribbean: 1980-2015.

OBJECTIVES: In Latin America and the Caribbean (LAC), pertussis disease incidence has reportedly increased since 2000 despite high vaccine coverage. A systematic review of pertussis literature and a meta-analysis was conducted to understand the burden of disease in LAC. METHODS: A systematic literature review was completed, using relevant search terms. Original articles describing pertussis epidemiology and vaccine coverage in LAC published between 1980 and 2015 were identified. Applying a Bayesian meta-analysis random-effects model, we calculated pooled estimates and corresponding 95% credible intervals (95% CrIs) for pertussis incidence, case fatality ratio (CFR), pertussis prevalence among contacts, and coverage with three doses of diphtheria, tetanus, and pertussis (DTP) vaccine (DTP3). RESULTS: A total of 59 studies meeting our selection criteria were identified, representing 15 countries. Of the 59, 15 of them provided incidence data, with 7 of the 15 reporting a pertussis case definition. The pertussis incidence estimate for the 1980-1999 period was 17.8 cases per 100 000 persons (95% CrI: 5.9-29.7); for the 2000-2015 period, it was 2.5 cases per 100 000 persons (95% CrI: 1.8-3.2). For the 1980-2015 period, the CFR, in 19 studies reviewed, was 3.9% (95% CrI: 2.9%-4.9%); for that same period, in 5 studies reviewed, pertussis prevalence among contacts was 24.9% (95% CrI: 13.7%-36.1%). Pooled DTP3 vaccine coverage estimates, in a total of 20 studies reviewed for the following three time periods, were: 1980-1990, 72.4% (95% CrI: 64.6%-80.2%); 1991-2000, 79.0% (95% CrI: 66.1%-91.9%); and 2001-2015, 90.0% (95% CrI: 87.7%-92.3%). CONCLUSION: A decrease in pertussis incidence and an achievement of moderately high DTP3 vaccine coverage since the early 2000s was observed. The review highlights the need for increased publication of pertussis data at the country level and for LAC as a whole in order to better understand the true burden of the disease. Application of a standardized case definition and use of active case finding would aid in obtaining more accurate estimates of the disease burden in LAC.

Systematic review and meta-analysis of pertussis epidemiology in Latin America and the Caribbean: 1980-2015 / Examen sistemático y metanálisis de las características epidemiológicas de la tos ferina en América Latina y el Caribe: 1980-2015 / Revisão sistemática e metanálise da epidemiologia da coqueluche na América Latina e Caribe: 1980 a 2015

Objectives In Latin America and the Caribbean (LAC), pertussis disease incidence has reportedly increased since 2000 despite high vaccine coverage. A systematic review of pertussis literature and a meta-analysis was conducted to understand the burden of disease in LAC. Methods A systematic literature review was completed, using relevant search terms. Original articles describing pertussis epidemiology and vaccine coverage in LAC published between 1980 and 2015 were identified. Applying a Bayesian meta-analysis random-effects model, we calculated pooled estimates and corresponding 95% credible intervals (95% CrIs) for pertussis incidence, case fatality ratio (CFR), pertussis prevalence among contacts, and coverage with three doses of diphtheria, tetanus, and pertussis (DTP) vaccine (DTP3). Results A total of 59 studies meeting our selection criteria were identified, representing 15 countries. Of the 59, 15 of them provided incidence data, with 7 of the 15 reporting a pertussis case definition. The pertussis incidence estimate for the 1980-1999 period was 17.8 cases per 100 000 persons (95% CrI: 5.9-29.7); for the 2000-2015 period, it was 2.5 cases per 100 000 persons (95% CrI: 1.8-3.2). For the 1980-2015 period, the CFR, in 19 studies reviewed, was 3.9% (95% CrI: 2.9%-4.9%); for that same period, in 5 studies reviewed, pertussis prevalence among contacts was 24.9% (95% CrI: 13.7%-36.1%). Pooled DTP3 vaccine coverage estimates, in a total of 20 studies reviewed for the following three time periods, were: 1980-1990, 72.4% (95% CrI: 64.6%-80.2%); 1991-2000, 79.0% (95% CrI: 66.1%-91.9%); and 2001-2015, 90.0% (95% CrI: 87.7%-92.3%). Conclusion A decrease in pertussis incidence and an achievement of moderately high DTP3 vaccine coverage since the early 2000s was observed. The review highlights the need for increased publication of pertussis data at the country level and for LAC as a whole in order to better understand the true burden of the disease. Application of a standardized case definition and use of active case finding would aid in obtaining more accurate estimates of the disease burden in LAC.

RESUMEN Objetivos En América Latina y el Caribe, la incidencia de la tos ferina habría aparentemente aumentado desde el 2000, a pesar de la alta cobertura de vacunación. Se realizó una revisión sistemática de la bibliografía sobre tos ferina y un metanálisis para conocer la carga de esta enfermedad en América Latina y el Caribe. Métodos. La revisión bibliográfica sistemática se realizó utilizando términos de búsqueda pertinentes. Se encontraron artículos originales que describían las características epidemiológicas de la tos ferina y la cobertura de vacunación en América Latina y el Caribe publicados entre 1980 y el 2015. Aplicando un modelo bayesiano de efectos aleatorios para el metanálisis, se obtuvieron estimaciones combinadas y los correspondientes intervalos de credibilidad del 95% (ICr) para la incidencia, la tasa de letalidad y la prevalencia entre contactos de la tos ferina, y la cobertura con tres dosis de vacuna contra la difteria, el tétanos y la tos ferina (DTP3). Resultados Se encontraron en total 59 estudios de 15 países que cumplían con los criterios de selección. De ellos, 15 proporcionaban datos sobre incidencia. Siete de estos 15 contenían una definición de caso de tos ferina. La incidencia estimada de tos ferina para el período 1980-1999 fue de 17,8 casos por 100 000 (ICr 95%: 5,9-29,7) y para el período 2000-2015, de 2,5 casos por 100 000 (ICr 95%: 1,8-3,2). En cuanto a la tasa de letalidad, para el período 1980-2015 en 19 estudios examinados fue de 3,9% (ICr 95%: 2,9%-4,9%); en el mismo período, en 5 estudios examinados la prevalencia de tos ferina entre los contactos fue de 24,9% (ICr 95%: 13,7%-36,1%). Las estimaciones combinadas de cobertura con DTP3 en un total de 21 estudios examinados para los siguientes tres períodos fueron: en 1980-1990, 72,4% (ICr 95%: 64,6%-80,2%); en 1991-2000, 79,0% (ICr 95%: 66,1%-91,9%) y en el 2001-2015, 90,0% (ICr 95%: 87,7%-92,3%). Conclusiones Se observó una disminución de la incidencia de la tos ferina y el logro de una cobertura moderadamente alta con la vacuna DTP3 desde principios del siglo XXI. En el examen se subraya la necesidad de incrementar la publicación de datos sobre la tos ferina en los países y en América Latina y el Caribe en su conjunto, para conocer mejor la verdadera carga de enfermedad. La adopción de una definición de caso normalizada y la búsqueda activa de casos ayudarán a obtener estimaciones más precisas de la carga de enfermedad en América Latina y el Caribe.

RESUMO Objetivos Há relatos de que a incidência de coqueluche na América Latina e Caribe (ALC) tem aumentado desde o ano 2000, apesar da alta cobertura vacinal. Realizamos uma revisão sistemática e metanálise da literatura sobre a coqueluche para compreender a carga da doença na ALC. Métodos. Fizemos uma revisão sistemática da literatura usando termos de pesquisa relevantes. Identificamos artigos originais, publicados entre 1980 e 2015, que descrevessem a epidemiologia da coqueluche e a cobertura vacinal na ALC. Aplicando um modelo Bayesiano de efeitos aleatórios para a metanálise, calculamos estimativas agrupadas e seus correspondentes intervalos de credibilidade de 95% (CrIs 95%) para a incidência de coqueluche, a taxa de letalidade, a prevalência de coqueluche entre os contatos e a cobertura com três doses da vacina combinada para difteria, tétano e coqueluche (DTP3). Resultados Identificamos um total de 59 estudos que cumpriram os nossos critérios de seleção, representando 15 países. Destes 59, 15 apresentaram dados sobre a incidência, e 7 dos 15 apresentaram uma definição de "caso de coqueluche". A incidência estimada da coqueluche no período de 1980 a 1999 foi de 17,8 casos por 100.000 pessoas (CrI 95%: 5,9-29,7); no período de 2000 a 2015, foi de 2,5 casos por 100.000 pessoas (CrI 95%: 1,8-3,2). No período de 1980 a 2015, a taxa de letalidade, em 19 estudos revistos, foi de 3,9% (CrI 95%: 2,9%-4,9%); neste mesmo período, em 5 estudos revistos, a prevalência de coqueluche entre os contatos foi de 24,9% (CrI 95%: 13,7%-36,1%). A cobertura vacinal agrupada com DTP3, em um total de 21 estudos examinados nos seguintes três períodos, foi estimada em: 1980 a 1990, 72,4% (CrI 95%: 64,6%-80,2%); 1991 a 2000, 79,0% (CrI 95%: 66,1%-91,9%); 2001 a 2015, 90,0% (CrI 95%: 87,7%-92,3%). Conclusões Foi observada uma redução na incidência de coqueluche e uma cobertura vacinal com DTP3 relativamente alta desde o início da década de 2000. Esta revisão destaca a necessidade de melhorar a publicação de dados sobre a coqueluche ao nível nacional e na ALC como um todo, a fim de promover uma melhor compreensão sobre a verdadeira carga da doença. O uso de uma definição padronizada de "caso de coqueluche" e a busca ativa de casos ajudaria na obtenção de estimativas mais precisas da carga da doença na ALC.

Long-Term Exposure to Ozone and Life Expectancy in the United States, 2002 to 2008.

Long-term exposure to ground-level ozone is associated with increased risk of morbidity and mortality. The association remains uncertain between long-term exposure to ozone and life expectancy. We assessed the associations between seasonal mean daily 8-hour maximum (8-hr max) ozone concentrations measured during the ozone monitoring seasons and life expectancy at birth in 3109 counties of the conterminous U.S. during 2002 to 2008. We used latent class growth analysis to identify latent classes of counties that had distinct mean levels and rates of change in ozone concentrations over the 7-year period and used linear regression analysis to determine differences in life expectancy by ozone levels. We identified 3 classes of counties with distinct seasonal mean daily 8-hr max ozone concentrations and rates of change. When compared with the counties with the lowest ozone concentrations, the counties with the highest ozone concentrations had 1.7- and 1.4-year lower mean life expectancy in males and females (both P < 0.0001), respectively. The associations remained statistically significant after controlling for potential confounding effects of seasonal mean PM2.5 concentrations and other selected environmental, demographic, socio-economic, and health-related factors (both P < 0.0001). A 5 ppb higher ozone concentration was associated with 0.25 year lower life expectancy in males (95% CI: -0.30 to -0.19) and 0.21 year in females (95% CI: -0.25 to -0.17). We identified 3 classes of counties with distinct mean levels and rates of change in ozone concentrations. Our findings suggest that long-term exposure to a higher ozone concentration may be associated with a lower life expectancy.

Geographic Variation in the Association between Ambient Fine Particulate Matter (PM2.5) and Term Low Birth Weight in the United States.

BACKGROUND: Studies on the association between prenatal exposure to fine particulate matter ≤ 2.5 µm in aerodynamic diameter (PM2.5) and term low birth weight (LBW) have resulted in inconsistent findings. Most studies were conducted in snapshots of small geographic areas and no national study exists. OBJECTIVES: We investigated geographic variation in the associations between ambient PM2.5 during pregnancy and term LBW in the contiguous United States. METHODS: A total of 3,389,450 term singleton births in 2002 (37-44 weeks gestational age and birth weight of 1,000-5,500 g) were linked to daily PM2.5 via imputed birth days. We generated average daily PM2.5 during the entire pregnancy and each trimester. Multi-level logistic regression models with county-level random effects were used to evaluate the associations between term LBW and PM2.5 during pregnancy. RESULTS: Without adjusting for covariates, the odds of term LBW increased 2% [odds ratio (OR) = 1.02; 95% CI: 1.00, 1.03] for every 5-µg/m(3) increase in PM2.5 exposure during the second trimester only, which remained unchanged after adjusting for county-level poverty (OR = 1.02; 95% CI: 1.01, 1.04). The odds did change to null after adjusting for individual-level predictors (OR = 1.00; 95% CI: 0.99, 1.02). Multi-level analyses, stratified by census division, revealed significant positive associations of term LBW and PM2.5 exposure (during the entire pregnancy or a specific trimester) in three census divisions of the United States: Middle Atlantic, East North Central, and West North Central, and significant negative association in the Mountain division. CONCLUSIONS: Our study provided additional evidence on the associations between PM2.5 exposure during pregnancy and term LBW from a national perspective. The magnitude and direction of the estimated associations between PM2.5 exposure and term LBW varied by geographic locations in the United States.