Characteristics and Clinical Prognosis of Septic Patients With Persistent Lymphopenia.

Background: Septic patients with persistent lymphopenia may be in an immunosuppressed state. Therefore, we evaluated and compared the clinical characteristics and outcomes of septic patients with persistent lymphopenia (≥2d) and those with nonpersistent lymphopenia. Methods: A retrospective cohort study was designed. A total of 1306 patients with sepsis who were attended to the First Affiliated Hospital of Dalian Medical University from March 2016 to August 2022 were included. The primary clinical outcome was 90d mortality. The secondary clinical outcomes were the length of stay, hospital mortality, 28d mortality, the incidence of secondary infection, and differences in clinical characteristics. Results: Among 1306 patients with sepsis, 913 (69.9%) patients developed persistent lymphopenia. Compared with patients with nonpersistent lymphopenia, patients with persistent lymphocytopenia were admitted to intensive care unit (75.7% vs 52.7%, P < .05), treated with mechanical ventilation (67.6% vs 39.2%, P < .05), positive rate of microbial culture pathogens (86.7% vs 71.2%, P < .05), SOFA [8.0 (6.0-10.0) vs 6.0 (4.0-8.0), P < .05], length of stay [17.0d (12.0-27.0) vs 13.0d (10.0-21.0), P < .05], hospital mortality (37.7% vs 24.2%, P < .05), 28d mortality (38.0% vs 22.9%, P < .05), and 90d mortality (51.2% vs 31.3%, P < .05) were higher. As the duration of lymphocytopenia increased, so did the mortality rate in hospital. In addition, the onset time of persistent lymphopenia was not associated with SOFA. But we found that the frequency of persistent lymphopenia during hospitalization was positively associated with SOFA. Conclusion: Septic patients with persistent lymphopenia have higher mortality, worse conditions, increased risk of secondary infection, and poor prognosis regardless of shock.

Activating transcription factor 3: A potential therapeutic target for inflammatory pulmonary diseases.

BACKGROUND: Activating transcription factor 3 (ATF3) is a nuclear protein that is widely expressed in a variety of cells. It is a stress-inducible transcription gene and a member of the activating transcription factor/cAMP responsive element-binding protein (ATF/CREB) family. METHODS: The comprehensive literature review was conducted by searching PubMed and Google Scholar. Search terms used were "ATF3", "ATF3 and (ALI or ARDS)", "ATF3 and COPD", "ATF3 and PF", and "ATF3 and Posttranslational modifications". RESULTS: Recent studies have shown that ATF3 plays a critical role in many inflammatory pulmonary diseases, including acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF). ATF3 participates in many signaling pathways and complex pathophysiological processes, such as inflammation, immunity, endoplasmic reticulum stress, and cell proliferation. However, the role of ATF3 in current studies is controversial, and there are reports showing that ATF3 plays different roles in different pulmonary diseases. CONCLUSIONS: In this review, we first summarized the structure, function, and mechanism of ATF3 in various inflammatory pulmonary diseases. The impact of ATF3 on disease pathogenesis and the clinical implications was particularly focused on, with an overall aim to identify new targets for treating inflammatory pulmonary diseases.

High-efficiency metalens-based compact multispectral variable spectrometer.

Conventional spectrometers are bulky, and researchers have continuously made efforts in their miniaturization and integration in recent years. Among these studies, metalenses have attracted immense interest because of their merits of a flat shape and flexible regulation. Herein, we introduce a design of a polarization-insensitive metalens-based spectrometer that utilizes an off-axis high-efficiency broadband metalens in the wavelength range of 500-1000 nm. The demonstrated metalens consisting of nanopillars employs propagation phase and phase function optimization methods and can achieve spectral resolutions of 0.6 nm with efficiency as high as 77%. By stitching metalenses with different focal lengths, the functionality of the spectrometer can be expanded. Hence, a compact variable design with favorable focusing and dispersive properties can be achieved by one single component instead of traditional cascading optics, thus shrinking the volume to the millimeter scale and reducing cost. This research proves the potential for applications of metalenses in spectrometers as well as other consumer and industry products.

Human herpesvirus 7 encephalitis in an immunocompetent adult and a literature review.

BACKGROUND: Human herpesvirus 7 (HHV-7) is a common virus that infects children early and is accompanied by lifelong latency in cells, which is easy to reactivate in immunodeficient adults, but the underlying pathological mechanism is uncertain in immunocompetent adults without peculiar past medical history. Even though the clinical manifestation of the encephalitis caused by HHV-7 is uncommon in immunocompetent adults, the HHV-7 infection should not be neglected for encephalitis for unknown reasons. CASE PRESENTATION: We reported here a case of HHV-7 encephalitis with epileptic seizures. While the brain computer tomography was standard, electroencephalography displayed slow waves in the temporal and bilateral frontal areas, then HHV-7 DNA was detected in the metagenomic next-generation sequencing of cerebrospinal fluid. Fortunately, the patient recovered after treatment and was discharged 2 months later. We also collected the related cases and explored a better way to illuminate the underlying mechanism. CONCLUSION: The case indicates clinicians should memorize HHV-7 as an unusual etiology of encephalitis to make an early diagnosis and therapy.

Compression of hyperspectral images based on Tucker decomposition and CP decomposition.

Hyperspectral imagers are developing towards high resolution, high detection sensitivity, broad spectra, and wide coverage, which means that hyperspectral data are getting more and more substantial. This brings a great challenge to data storage and real-time transmission of hyperspectral data. A compression method based on Tucker decomposition and CANDECOMP/PARAFAC decomposition (TD-CP) is proposed. The hyperspectral data are treated as a third-order tensor. First, TD is performed on the hyperspectral data to obtain a core tensor and three factor matrices, and then CP decomposition is performed on the core tensor. Compared with principal component analysis (PCA)+JPEG2000, TD, and CP, TD-CP can retain spatial information and spectral information better at the same time, and running time is shorter.

Compact Shortwave Infrared Imaging Spectrometer Based on a Catadioptric Prism.

This article demonstrates a compact prism imaging spectrometer method. A catadioptric curved prism is located at the secondary mirror position of the spectrometer and used to balance the aberrations, enlarge the dispersion width, and decrease the volume. A mathematical model of the prism and spectrometer is derived, which provides an optimal initial structure for a non-coaxial spectrometer, simplifying the optical design process and reducing the system volume. Using this method, a compact shortwave infrared imaging spectrometer with a 16° field of view is designed with an F-number/3, and the measured spectrum ranges from 0.95 to 2.5 µm. The performance is analyzed and evaluated. Laboratory testing results prove the excellent optical performance, and under the same specifications, the spectrometer length decreases by 40%.

Wide-field grating-prism imaging spectrometer: optical design and implementation.

A wide-field imaging spectrometer based on a grating prism is proposed. The grating and prism parameters are discussed to balance spectral distortion over the entire band. The design method of the grating-prism (GP) dispersive module and the catadioptric optics of the spectrometer are discussed in detail. A high optical speed (F/2.4) and long slit (29.4 mm) visible and near-infrared design with high image quality and small distortion is presented. The results show that the optical performance of the GP imaging spectrometer is excellent. The tolerance analysis indicates that the GP spectrometer can be easily manufactured and implemented. The prototype has been tested in the laboratory and outdoors, and the results confirmed that the design will be useful in the fields of aeronautics and astronautics.

Distortion correction based on off-axis Schwarzschild two-mirror hyperspectral imager.

A new method of distortion correction based on the off-axis Schwarzschild two-mirror hyperspectral imager is proposed in this paper. The polynomial model is used to indicate the distortion in the pushbroom direction and the correction method is based on linear feature. The radial distortion model is used to indicate the vertical pushbroom direction of distortion and the correction method is based on the cross ratio invariance. Compared with the common precision angle measurement method, this method is simple and efficient. This method can be applied to the distortion correction of the non-mapping pushbroom hyperspectral imager.

Design of a compact wide-spectrum double-channel prism imaging spectrometer with freeform surface.

A double-channel prism imaging spectrometer that includes visible-near-infrared (VNIR) and shortwave-infrared (SWIR) spectra is presented. Double slits divide a wide spectral band into two independent channels for VNIR and SWIR, guaranteeing their independent spectral resolution. A beam splitter splits the band into two, one detected by the SWIR and the other by the VNIR detector. The freeform surface, as a mirror, compensates for astigmatism across a wide spectral band. An imaging spectrometer with 30° field of view and a measured spectrum from 400 nm to 2500 nm is designed. This compact, cost-effective spectrometer with high performance and small spectral distortion has a huge potential for broadband space exploration.

Design and fabrication of a compact off-axis see-through head-mounted display using a freeform surface.

Head-mounted display (HMD) has been widely used in many fields, and most existing HMDs are complex and typically non-aesthetically pleasing. In this paper, a novel compact, lightweight and wearable off-axis HMD with freeform surface is reported. It is challenging to achieve large field of view (FOV) and maintain compact structure simultaneously for this type system. In this design, the compact off-axis HMD consists of a tilted ellipsoid combiner and a four pieces relay lenses. It offers a diagonal FOV of 30°, and an exit pupil diameter of 7 mm. No diffractive surfaces are used, thus avoiding the effect of stray light and ghost image in previous designs. The x-y polynomial freeform surface is adopted in the relay lens for improving the image quality and minimizing the structure size. Analytical expressions to determine the initial structure of HMD has been given, while structure constrains, optimization strategy and tolerance analysis are also described in details. The optical system is easy to manufacture by ordinary method which is beneficial for mass production. Further, a prototype of this compact HMD is successfully implemented with good imaging performance. The compact structure of HMD makes it well suited for integrating a normal glass, significantly advancing the application of HMD in people's daily life.

[Design and implementation of real-time processing platform for movement error correction of hyperspectrual imaging].

The approach that deals with compressed and packed image data transmitted from satellite to the ground is too slow for real-time application occasion, it also has huge image, multi-processing step and complexity recovery arithmetic synchronously, so it is urgent to build accurate and fast data processing platform for real-time processing. For the moment, the platform for data recovery and error correction is much less, the so-called successful platform may directly affect the effect of target detection and identification because of processing speed, precision, flexibility, configuration and upgrade. The platform we build is to set spatial modulation spectrometer as the research goal, We design and implement a hardware platform based on Xilinx Virtex-5 FPGA, It is combined with ISE IP soft-core resources which is configurable, high-precision and flexible by focusing on analyzing key aspects of the hardware platform. And the relevant test data were drawn, then a good way for spectrum recovery and error correction was explored.

[Design of a dual-channel Mach-Zehnder lateral shearing interferometer for the large aperture static imaging spectrometer].

Large aperture static imaging spectrometry (LASIS) is a kind of joint temporally and spatially modulated Fourier transform imaging spectrometry. In such instruments, lateral shearing interferometer is a key element, the most frequently used type of which is the Sagnac interferometer. In this configuration, one half of the light entering the interferometer backtracks and causes a great decrease in energy efficiency. The present paper proposes a modified Mach-Zehnder lateral shearing interferometer structure to tackle this problem. With the ability to produce the same lateral shear, it features the advantage of dual channel output. We present a ray tracing procedure to induce the general expression of the lateral shear as well as analyze the contributions of error sources to the shear accuracy. The results serve as a new idea for the design of large aperture static imaging spectrometers and can be used to instruct the design and optimization of this kind of imaging spectrometer.

[Advance in imaging spectropolarimeter].

Imaging spectropolarimeter (ISP) is a type of novel photoelectric sensor which integrated the functions of imaging, spectrometry and polarimetry. In the present paper, the concept of the ISP is introduced, and the advances in ISP at home and abroad in recent years is reviewed. The principles of ISPs based on novel devices, such as acousto-optic tunable filter (AOTF) and liquid crystal tunable filter (LCTF), are illustrated. In addition, the principles of ISPs developed by adding polarized components to the dispersing-type imaging spectrometer, spatially modulated Fourier transform imaging spectrometer, and computer tomography imaging spectrometer are introduced. Moreover, the trends of ISP are discussed too.

[Study and simulation of the intensity modulation-Fourier transform spectropolarimeter].

Intensity modulation-Fourier transform spectropolarimetry (IMFTSP) is a novel technology that combines the intensity modulation spectropolarimetry and Fourier transform spectroscopy. The IMFTSP can obtain full Stokes spectropolarimetric parameters simultaneously, and maintains the throughput (Jacquinot) and multiplex (Fellgett) advantages. Yet aside from this, the IMFTSP has the advantage of reducing the complexity of data processing. The data collecting and spectropolarimetric parameters reconstruction processes were analyzed theoretically in this paper, the theoretical formulas are presented, and a whole process mathematical simulation for the IMFTSP system is introduced. The theory analysis and simulation results proved the feasibility of the IMFTSP.

[Advance in interferogram data processing technique].

Fourier transform spectrometry is a type of novel information obtaining technology, which integrated the functions of imaging and spectra, but the data that the instrument acquired is the interference data of the target, which is an intermediate data and couldn't be used directly, so data processing must be adopted for the successful application of the interferometric data In the present paper, data processing techniques are divided into two classes: general-purpose and special-type. First, the advance in universal interferometric data processing technique is introduced, then the special-type interferometric data extracting method and data processing technique is illustrated according to the classification of Fourier transform spectroscopy. Finally, the trends of interferogram data processing technique are discussed.

[Spectral discrimination method information divergence combined with gradient angle].

The present paper proposes a spectral discrimination method combining spectral information divergence with spectral gradient angle (SID x tan(SGA(pi/2)) which overcomes the shortages of the existing methods which can not take the whole spectral shape and local characteristics into account simultaneously. Using the simulation spectra as input data, according to the interferogram acquirement principle and spectrum recovery algorithm of the temporally and spatially modulated Fourier transform imaging spectrometer (TSMFTIS), we simulated the distortion spectra recovery process of the TMSFTIS in different maximum mix ratio and distinguished the difference between the recovered spectra and the true spectrum by different spectral discrimination methods. The experiment results show that the SID x tan(SGA(pi/2)) can not only identify the similarity of the whole spectral shapes, but also distinguish local differences of the spectral characteristics. A comparative study was conducted among the different discrimination methods. The results have validated that the SID x tan(SGA(pi/2)) has a significant improvement in the discriminatory ability.

[General expression of optic path difference of reflecting rotating Fourier transform spectrometer].

The principle of reflecting rotating Fourier transform spectrometer was introduced in the present paper. Based on the Malus law and reflecting characteristic of cube corner, the optic path difference of reflecting rotating Fourier transform spectrometer was analyzed and calculated by choosing the center of rotating mirror as a reference point of the aplanatic surface of incidence beam and return beam. General expression of optic path difference at any time and maximal optic path difference of reflecting rotating Fourier transform spectrometer was presented. The factors that influence the maximal optic path difference and the period of optic path difference were analyzed. The results provide a theoretical guidance for design and manufacture of reflecting rotating Fourier transform spectrometer.

[Spatial domain display for interference image dataset].

The requirements of imaging interferometer visualization is imminent for the user of image interpretation and information extraction. However, the conventional researches on visualization only focus on the spectral image dataset in spectral domain. Hence, the quick show of interference spectral image dataset display is one of the nodes in interference image processing. The conventional visualization of interference dataset chooses classical spectral image dataset display method after Fourier transformation. In the present paper, the problem of quick view of interferometer imager in image domain is addressed and the algorithm is proposed which simplifies the matter. The Fourier transformation is an obstacle since its computation time is very large and the complexion would be even deteriorated with the size of dataset increasing. The algorithm proposed, named interference weighted envelopes, makes the dataset divorced from transformation. The authors choose three interference weighted envelopes respectively based on the Fourier transformation, features of interference data and human visual system. After comparing the proposed with the conventional methods, the results show the huge difference in display time.

[Developments and trends of the computed tomography imaging spectrometers].

The present paper reviews the computed tomography imaging spectrometer (CTIS) measurement systems at home and abroad from the aspects of technological characterizations and research focuses. The developments of computed tomography imaging spectrometers are described, involving the adding new abilities by improving systematic structure and by incorporating other elements or systems, the study and applications of novel grating elements, detectors or apparatus, the optimizations and improvements of the system calibration methods and reconstruction algorithms. In addition, based on the classification of application scope, the extension status of probing spectral bands and application fields towards computed tomography imaging spectrometers and related systems are summarized. The principles of non-scanning computed tomography imaging spectrometer and high-throughput computed tomography imaging spectrometer are introduced. Moreover, the trends of computed tomography imaging spectrometers are discussed too.

[Comparison of correction methods for nonlinear optic path difference of reflecting rotating Fourier transform spectrometer].

The principle of reflecting rotating Fourier transform spectrometer was introduced in the present paper. The nonlinear problem of optical path difference (OPD) of rotating Fourier transform spectrometer universally exists, produced by the rotation of rotating mirror. The nonlinear OPD will lead to fictitious recovery spectrum, so it is necessary to compensate the nonlinear OPD. Three methods of correction for the nonlinear OPD were described and compared in this paper, namely NUFFT method, OPD replace method and interferograms fitting method. The result indicates that NUFFT was the best method for the compensation of nonlinear OPD, OPD replace method was better, its precision was almost the same as NUFFT method, and their relative error are superior to 0.13%, but the computation efficiency of OPD replace method is slower than NUFFT method, while the precision and computation efficiency of interferograms fitting method are not so satisfied, because the interferograms are rapid fluctuant especially around the zero optical path difference, so it is unsuitable for polynomial fitting, and because this method needs piecewise fitting, its computation efficiency is the slowest, thus the NUFFT method is the most suited method for the nonlinear OPD compensation of reflecting rotating Fourier transform spectrometer.