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1.
Proc Natl Acad Sci U S A ; 119(31): e2206400119, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35905324

RESUMEN

Phytochromes are ubiquitous photoreceptor proteins that undergo a significant refolding of secondary structure in response to initial photoisomerization of the chromophoric group. This process is important for the signal transduction through the protein and thus its regulatory function in different organisms. Here, we employ two-dimensional infrared absorption (2D-IR) spectroscopy, an ultrafast spectroscopic technique that is sensitive to vibrational couplings, to study the photoreaction of bacterial phytochrome Agp1. By calculating difference spectra with respect to the photoactivation, we are able to isolate sharp difference cross-peaks that report on local changes in vibrational couplings between different sites of the chromophore and the protein. These results indicate inter alia that a dipole coupling between the chromophore and the so-called tongue region plays a role in stabilizing the protein in the light-activated state.


Asunto(s)
Proteínas Bacterianas , Fitocromo , Proteínas Bacterianas/química , Fitocromo/química , Análisis Espectral , Vibración
2.
Proc Natl Acad Sci U S A ; 119(5)2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-35078934

RESUMEN

The formation of ordered cross-ß amyloid protein aggregates is associated with a variety of human disorders. While conventional infrared methods serve as sensitive reporters of the presence of these amyloids, the recently discovered amyloid secondary structure of cross-α fibrils presents new questions and challenges. Herein, we report results using Fourier transform infrared spectroscopy and two-dimensional infrared spectroscopy to monitor the aggregation of one such cross-α-forming peptide, phenol soluble modulin alpha 3 (PSMα3). Phenol soluble modulins (PSMs) are involved in the formation and stabilization of Staphylococcus aureus biofilms, making sensitive methods of detecting and characterizing these fibrils a pressing need. Our experimental data coupled with spectroscopic simulations reveals the simultaneous presence of cross-α and cross-ß polymorphs within samples of PSMα3 fibrils. We also report a new spectroscopic feature indicative of cross-α fibrils.


Asunto(s)
Amiloide/genética , Toxinas Bacterianas/genética , Polimorfismo Genético/genética , Espectrofotometría Infrarroja/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Staphylococcus aureus/genética
3.
BMC Genomics ; 25(1): 671, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38970011

RESUMEN

BACKGROUND: The dirigent (DIR) genes encode proteins that act as crucial regulators of plant lignin biosynthesis. In Solanaceae species, members of the DIR gene family are intricately related to plant growth and development, playing a key role in responding to various biotic and abiotic stresses. It will be of great application significance to analyze the DIR gene family and expression profile under various pathogen stresses in Solanaceae species. RESULTS: A total of 57 tobacco NtDIRs and 33 potato StDIRs were identified based on their respective genome sequences. Phylogenetic analysis of DIR genes in tobacco, potato, eggplant and Arabidopsis thaliana revealed three distinct subgroups (DIR-a, DIR-b/d and DIR-e). Gene structure and conserved motif analysis showed that a high degree of conservation in both exon/intron organization and protein motifs among tobacco and potato DIR genes, especially within members of the same subfamily. Total 8 pairs of tandem duplication genes (3 pairs in tobacco, 5 pairs in potato) and 13 pairs of segmental duplication genes (6 pairs in tobacco, 7 pairs in potato) were identified based on the analysis of gene duplication events. Cis-regulatory elements of the DIR promoters participated in hormone response, stress responses, circadian control, endosperm expression, and meristem expression. Transcriptomic data analysis under biotic stress revealed diverse response patterns among DIR gene family members to pathogens, indicating their functional divergence. After 96 h post-inoculation with Ralstonia solanacearum L. (Ras), tobacco seedlings exhibited typical symptoms of tobacco bacterial wilt. The qRT-PCR analysis of 11 selected NtDIR genes displayed differential expression pattern in response to the bacterial pathogen Ras infection. Using line 392278 of potato as material, typical symptoms of potato late blight manifested on the seedling leaves under Phytophthora infestans infection. The qRT-PCR analysis of 5 selected StDIR genes showed up-regulation in response to pathogen infection. Notably, three clustered genes (NtDIR2, NtDIR4, StDIR3) exhibited a robust response to pathogen infection, highlighting their essential roles in disease resistance. CONCLUSION: The genome-wide identification, evolutionary analysis, and expression profiling of DIR genes in response to various pathogen infection in tobacco and potato have provided valuable insights into the roles of these genes under various stress conditions. Our results could provide a basis for further functional analysis of the DIR gene family under pathogen infection conditions.


Asunto(s)
Evolución Molecular , Familia de Multigenes , Nicotiana , Filogenia , Proteínas de Plantas , Solanum tuberosum , Solanum tuberosum/genética , Solanum tuberosum/microbiología , Nicotiana/genética , Nicotiana/microbiología , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Estrés Fisiológico/genética , Regiones Promotoras Genéticas , Duplicación de Gen , Ralstonia solanacearum , Genes de Plantas
4.
Glob Chang Biol ; 30(3): e17239, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38500015

RESUMEN

Dissimilatory iron reduction (DIR) can drive the release of organic carbon (OC) as carbon dioxide (CO2 ) by mediating electron transfer between organic compounds and microbes. However, DIR is also crucial for carbon sequestration, which can affect inorganic-carbon redistribution via iron abiotic-phase transformation. The formation conditions of modern carbonate-bearing iron minerals (ICFe ) and their potential as a CO2 sink are still unclear. A natural environment with modern ICFe , such as karst lake sediment, could be a good analog to explore the regulation of microbial iron reduction and sequential mineral formation. We find that high porosity is conducive to electron transport and dissimilatory iron-reducing bacteria activity, which can increase the iron reduction rate. The iron-rich environment with high calcium and OC can form a large sediment pore structure to support rapid DIR, which is conducive to the formation and growth of ICFe . Our results further demonstrate that the minimum DIR threshold suitable for ICFe formation is 6.65 µmol g-1 dw day-1 . DIR is the dominant pathway (average 66.93%) of organic anaerobic mineralization, and the abiotic-phase transformation of Fe2+ reduces CO2 emissions by ~41.79%. Our findings indicate that as part of the carbon cycle, DIR not only drives mineralization reactions but also traps carbon, increasing the stability of carbon sinks. Considering the wide geographic distribution of DIR and ICFe , our findings suggest that the "iron mesh" effect may become an increasingly important vector of carbon sequestration.


Asunto(s)
Secuestro de Carbono , Hierro , Hierro/química , Hierro/metabolismo , Dióxido de Carbono , Oxidación-Reducción , Ciclo del Carbono , Compuestos Férricos/metabolismo
5.
J Appl Clin Med Phys ; : e14511, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39258711

RESUMEN

PURPOSE: Deformable image registration (DIR) has been increasingly used in radiation therapy (RT). The accuracy of DIR algorithms and how it impacts on the RT plan dosimetrically were examined in our study for abdominal sites using biomechanically modeled deformations. METHODS: Five pancreatic cancer patients were enrolled in this study. Following the guidelines of AAPM TG-132, a patient-specific quality assurance (QA) workflow was developed to evaluate DIR for the abdomen using the TG-132 recommended virtual simulation software ImSimQA (Shrewsbury, UK). First, the planning CT was deformed to simulate respiratory motion using the embedded biomechanical model in ImSimQA. Additionally, 5 mm translational motion was added to the stomach, duodenum, and small bowel. The original planning CT and the deformed CT were then imported into Eclipse and MIM to perform DIR. The output displacement vector fields (DVFs) were compared with the ground truth from ImSimQA. Furthermore, the original treatment plan was recalculated on the ground-truth deformed CT and the deformed CT (with Eclipse and MIM DVF). The dose errors were calculated on a voxel-to-voxel basis. RESULTS: Data analysis comparing DVF from Eclipse versus MIM show the average mean DVF magnitude errors of 2.8 ± 1.0  versus 1.1 ± 0.7 mm for stomach and duodenum, 5.2 ± 4.0  versus 2.5 ± 1.0 mm for small bowel, and 4.8 ± 4.1  versus 2.7 ± 1.1 mm for the gross tumor volume (GTV), respectively, across all patients. The mean dose error on stomach+duodenum and small bowel were 2.3 ± 0.6% for Eclipse, and 1.0 ± 0.3% for MIM. As the DIR magnitude error increases, the dose error range increase, for both Eclipse and MIM. CONCLUSION: In our study, an initial assessment was conducted to evaluate the accuracy of DIR and its dosimetric impact on radiotherapy. A patient-specific DIR QA workflow was developed for pancreatic cancer patients. This workflow exhibits promising potential for future implementation as a clinical workflow.

6.
Mult Scler ; 29(13): 1688-1692, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37712415

RESUMEN

Cortical lesions (CLs) detected with double inversion recovery (DIR) magnetic resonance imaging (MRI) are very helpful in differentiating multiple sclerosis (MS) from other neuroinflammatory diseases of the central nervous system (CNS), that is, neuromyelitis optica spectrum disorders (NMOSDs). Furthermore, CLs are closely related to motor and cognitive impairment. We report a case of a 48-year-old female MS patient who developed several CLs during anti-CD20 therapy. Some CLs disappeared during follow-up MRIs. In the suspicion of a treatment failure, the screening for the autologous hematopoietic stem cell transplant (AHSCT) was performed with the evidence of an atrial myxoma. In MS patients with new CLs, a comorbid ischemic pathology should be considered and carefully investigated.


Asunto(s)
Fibrilación Atrial , Esclerosis Múltiple , Mixoma , Neuromielitis Óptica , Femenino , Humanos , Persona de Mediana Edad , Fibrilación Atrial/patología , Corteza Cerebral/patología , Esclerosis Múltiple/patología , Neuromielitis Óptica/patología , Imagen por Resonancia Magnética/métodos , Mixoma/diagnóstico por imagen , Mixoma/patología
7.
J Digit Imaging ; 36(2): 450-457, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36352165

RESUMEN

Automated co-registration and subtraction techniques have been shown to be useful in the assessment of longitudinal changes in multiple sclerosis (MS) lesion burden, but the majority depend on T2-fluid-attenuated inversion recovery sequences. We aimed to investigate the use of a novel automated temporal color complement imaging (CCI) map overlapped on 3D double inversion recovery (DIR), and to assess its diagnostic performance for detecting disease progression in patients with multiple sclerosis (MS) as compared to standard review of serial 3D DIR images. We developed a fully automated system that co-registers and compares baseline to follow-up 3D DIR images and outputs a pseudo-color RGB map in which red pixels indicate increased intensity values in the follow-up image (i.e., progression; new/enlarging lesion), blue-green pixels represent decreased intensity values (i.e., disappearing/shrinking lesion), and gray-scale pixels reflect unchanged intensity values. Three neuroradiologists blinded to clinical information independently reviewed each patient using standard DIR images alone and using CCI maps based on DIR images at two separate exams. Seventy-six follow-up examinations from 60 consecutive MS patients who underwent standard 3 T MR brain MS protocol that included 3D DIR were included. Median cohort age was 38.5 years, with 46 women, 59 relapsing-remitting type MS, and median follow-up interval of 250 days (interquartile range: 196-394 days). Lesion progression was detected in 67.1% of cases using CCI review versus 22.4% using standard review, with a total of 182 new or enlarged lesions using CCI review versus 28 using standard review. There was a statistically significant difference between the two methods in the rate of all progressive lesions (P < 0.001, McNemar's test) as well as cortical progressive lesions (P < 0.001). Automated CCI maps using co-registered serial 3D DIR, compared to standard review of 3D DIR alone, increased detection rate of MS lesion progression in patients undergoing clinical brain MRI exam.


Asunto(s)
Esclerosis Múltiple , Humanos , Femenino , Lactante , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/patología , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Aumento de la Imagen , Neuroimagen
8.
Proc Natl Acad Sci U S A ; 116(14): 6602-6607, 2019 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-30894486

RESUMEN

UV light and other factors damage crystallin proteins in the eye lens, resulting in cataracts that scatter light and affect vision. Little information exists about protein structures within these disease-causing aggregates. We examined postmortem lens tissue from individuals with and without cataracts using 2D infrared (2DIR) spectroscopy. Amyloid ß-sheet secondary structure was detected in cataract lenses along with denatured structures. No amyloid structures were found in lenses from juveniles, but mature lenses with no cataract diagnosis also contained amyloid, indicating that amyloid structures begin forming before diagnosis. Light scatters more strongly in regions with amyloid structure, and UV light induces amyloid ß-sheet structures, linking the presence of amyloid structures to disease pathology. Establishing that age-related cataracts involve amyloid structures gives molecular insight into a common human affliction and provides a possible structural target for pharmaceuticals as an alternative to surgery.


Asunto(s)
Amiloide , Catarata/metabolismo , Cápsula del Cristalino , Agregación Patológica de Proteínas/metabolismo , Rayos Ultravioleta , Anciano , Amiloide/química , Amiloide/metabolismo , Femenino , Humanos , Cápsula del Cristalino/química , Cápsula del Cristalino/metabolismo , Masculino , Estructura Secundaria de Proteína , Espectrofotometría Infrarroja
9.
Genomics ; 113(1 Pt 2): 979-990, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33144217

RESUMEN

DIRIGENT (DIR) genes play important roles in regulating plant growth and development and have been studied in many plant species. However, information on DIR genes in soybean is limited. Here, we identified and characterized 54 GmDIRs and studied the characteristics of GmDIRs. Most of the GmDIRs contained a classical gene structure, one exon; 26 conserved motifs were found among these GmDIRs. The GmDIRs were grouped into four subfamilies, DIR-a, DIR-b, DIR-e and DIR-f, based on a phylogenetic analysis, and 24 duplicated gene pairs were identified. Differences in the cis-acting elements in the GmDIR promoter regions might result in distinct expression patterns of GmDIRs in different tissues. In addition, GmDIR27 had a close relationship with the pod dehiscence gene GmPdh1, and overexpression of GmDIR27 increased pod dehiscence by affecting several pod dehiscence-related gene expressions. Generally, our results provide essential information that aids future efforts to functionally characterize soybean GmDIR genes.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Genes de Plantas , Glycine max/genética , Semillas/genética , Duplicación de Gen , Regulación de la Expresión Génica de las Plantas , Semillas/crecimiento & desarrollo , Glycine max/crecimiento & desarrollo , Glycine max/metabolismo
10.
Sensors (Basel) ; 22(14)2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35891086

RESUMEN

Inspection robots are widely used in the field of smart grid monitoring in substations, and partial discharge (PD) is an important sign of the insulation state of equipment. PD direction of arrival (DOA) algorithms using conventional beam forming and time difference of arrival (TDOA) require large-scale antenna arrays and high computational complexity, making them difficult to implement on inspection robots. To address this problem, a novel directional multiple signal classification (Dir-MUSIC) algorithm for PD direction finding based on signal strength is proposed, and a miniaturized directional spiral antenna circular array is designed in this paper. First, the Dir-MUSIC algorithm is derived based on the array manifold characteristics. This method uses strength intensity information rather than the TDOA information, which could reduce the computational difficulty and the requirement of array size. Second, the effects of signal-to-noise ratio (SNR) and array manifold error on the performance of the algorithm are discussed through simulations in detail. Then, according to the positioning requirements, the antenna array and its arrangement are developed and optimized. Simulation results suggested that the algorithm has reliable direction-finding performance in the form of six elements. Finally, the effectiveness of the algorithm is tested by using the designed spiral circular array in real scenarios. The experimental results show that the PD direction-finding error is 3.39°, which meets the need for partial discharge DOA estimation using inspection robots in substations.

11.
J Digit Imaging ; 35(4): 743-753, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35386033

RESUMEN

An increased number of healthcare providers across the continuum of care share responsibility for providing treatment and care to the patient. Treatment is often provided at community-based facilities and not necessarily at the hospital that performed the imaging. As a result, there is an increased dependency on readily available access to a patient's longitudinal imaging records. The ways in which diagnostic images and results are exchanged among providers within a patient's circle of care have expanded. This article explores three varieties of image exchange. First, we examine image exchange patterns within a regional Diagnostic Imaging Repository and identify missed sharing opportunities. Secondly, we explore the use of a regional clinical viewer widely used in southwestern Ontario, called ClinicalConnect™, and examine the adoption of the viewer by providers. Finally, the paper provides a high-level look at how patients can leverage patient portals to view their imaging data to empower their healthcare experience.


Asunto(s)
Intercambio de Información en Salud , Portales del Paciente , Atención a la Salud , Registros Electrónicos de Salud , Personal de Salud , Humanos , Ontario
12.
Molecules ; 27(15)2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35897969

RESUMEN

In order to explore a rapid identification method for the anti-counterfeit of commercial high value collections, a three-step infrared spectrum method was used for the pterocarpus collection identification to confirm whether a commercial pterocarpus bracelet (PB) was made from the precious species of Pterocarpus santalinus (P. santalinus). In the first step, undertaken by Fourier transform infrared spectroscopy (FTIR) spectrum, the absorption peaks intensity of PB was slightly higher than that of P. santalinus only at 1594 cm-1, 1205 cm-1, 1155 cm-1 and 836 cm-1. In the next step of second derivative IR spectra (SDIR), the FTIR features of the tested samples were further amplified, and the peaks at 1600 cm-1, 1171 cm-1 and 1152 cm-1 become clearly defined in PB. Finally, by means of two-dimensional correlation infrared (2DIR) spectrum, it revealed that the response of holocellulose to thermal perturbation was stronger in P. santalinus than that in PB mainly at 977 cm-1, 1008 cm-1, 1100 cm-1, 1057 cm-1, 1190 cm-1 and 1214 cm-1, while the aromatic functional groups of PB were much more sensitive to the thermal perturbation than those of P. santalinus mainly at 1456 cm-1, 1467 cm-1, 1518 cm-1, 1558 cm-1, 1576 cm-1 and 1605 cm-1. In addition, fluorescence microscopy was used to verify the effectiveness of the above method for wood identification and the results showed good consistency. This study demonstrated that the three-step IR method could provide a rapid and effective way for the anti-counterfeit of pterocarpus collections.


Asunto(s)
Pterocarpus , Pterocarpus/química , Espectrofotometría Infrarroja , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Madera
13.
Molecules ; 27(24)2022 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-36557982

RESUMEN

This study aims to collect information about soil investigation by FTIR. As we know, the FTIR technique is most often used in organic and bioorganic chemistry, while in geochemistry FTIR spectroscopy is not used very often. Therefore, there is a problem with the identification and interpretation of the IR spectra of minerals contained in sediments and soils. The reason for this is a deficiency of data about characteristic wavenumbers for minerals. Therefore, this study reviews and sums up, in one place, published articles that are connected to an investigation of minerals from 2002 to 2021 (based on the Scopus database). Additionally, the present review highlights various analytical techniques (ATR-FTIR, DRIFT, 2D-IR, and SR-FTIR) and discusses some of them for geochemical study. Additionally, the study describes helpful tools in the data pre-processing of IR spectra (normalization, baseline correction, and spectral derivatives).


Asunto(s)
Minerales , Suelo , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Espectrofotometría Infrarroja
14.
J Sci Food Agric ; 102(7): 3000-3009, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34773403

RESUMEN

BACKGROUND: Freshness is an important quality of squid with respect to determining the market price. The methods of evaluation of freshness fail to be widely used as a result of the lack of rapidity and quantitation. In the present study, a rapid and non-destructive quantification of squid freshness by Fourier transform infrared spectroscopy (FTIR) spectra combined with chemometric techniques was performed. RESULTS: The relatively linear content change of trimethylamine (TMA-N) and dimethylamine (DMA-N) of squid during storage at 4 °C indicated their feasibility as a freshness indicator, as also confirmed by sensory evaluation. The spectral changes were mainly caused by the degradation of proteins and the production of amines by two-dimensional infrared correlation spectroscopy, among which TMA-N, DMA-N and putrescine were the main amines. The successive projections algorithm (SPA) was employed to select the sensitive wavenumbers to freshness for modeling prediction including partial least-squares regression, support vector regression (SVR) and back-propagation artificial neural network. Generally, the SPA-SVR model of the selected characteristic wavenumber showed a higher prediction accuracy for DMA-N (R2 P  = 0.951; RMSEP  = 0.218), whereas both SPA-SVR (R2 P  = 0.929; RMSEP  = 2.602) and Full-SVR (R2 P  = 0.941; RMSEP  = 2.492) models had a higher predictive ability of TMA-N. CONCLUSION: The results of the present study demonstrate that FTIR spectroscopy coupled with multivariate calibration shows significant potential for the prediction of freshness in squid. © 2021 Society of Chemical Industry.


Asunto(s)
Decapodiformes , Alimentos Marinos , Algoritmos , Animales , Análisis de los Mínimos Cuadrados , Alimentos Marinos/análisis , Espectroscopía Infrarroja por Transformada de Fourier
15.
Entropy (Basel) ; 24(12)2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36554214

RESUMEN

Polar codes are closer to the Shannon limit with lower complexity in coding and decoding. As traditional decoding techniques suffer from high latency and low throughput, with the development of deep learning technology, some deep learning-based decoding methods have been proposed to solve these problems. Usually, the deep neural network is treated as a black box and learns to map the polar codes with noise to the original information code directly. In fact, it is difficult for the network to distinguish between valid and interfering information, which leads to limited BER performance. In this paper, a deep residual network based on information refinement (DIR-NET) is proposed for decoding polar-coded short packets. The proposed method works to fully distinguish the effective and interference information in the codewords, thus obtaining a lower bit error rate. To achieve this goal, we design a two-stage decoding network, including a denoising subnetwork and decoding subnetwork. This structure can further improve the accuracy of the decoding method. Furthermore, we construct the whole network solely on the basis of the attention mechanism. It has a stronger information extraction ability than the traditional neural network structure. Benefiting from cascaded attention modules, information can be filtered and refined step-by-step, thus obtaining a low bit error rate. The simulation results show that DIR-Net outperforms existing decoding methods in terms of BER performance under both AWGN channels and flat fading channels.

16.
Zhongguo Zhong Yao Za Zhi ; 47(11): 2890-2898, 2022 Jun.
Artículo en Zh | MEDLINE | ID: mdl-35718509

RESUMEN

The active components, mainly derived from secondary metabolites of medicinal plants, are the material basis for the efficacy of medicinal plants. Lignans, the secondary metabolites in plants with high bioactivity, are widely distributed in a variety of plant species, and their antiviral, antitumor, antibacterial, and antioxidant activities have been proved in clinical practice. Generally, lignans are diverse in structures with many chiral centers, and most of them are optically active. The biosynthesis of lignans depends on the oxidative coupling reaction through site selection and stereo selection, which impedes synthesized lignans to form racemates, but makes them in a three-dimensional configuration. Dirigent protein(DIR) plays an important role in guiding location selection and stereo selection of lignans in biosynthesis. In vitro studies on lignan biosynthesis have shown that racemic end products are obtained in the absence of DIR proteins, while the products in a three-dimensional configuration can be yielded in the presence of DIR proteins, indicating that DIR proteins play an asymmetric role in the biosynthesis of plant secondary metabolites. The present study reviewed the biolo-gical significance of DIR protein, the cloning of DIR gene, gene structure, catalytic mechanism, and the research progress in Isatis indigotica, Eucommia ulmoides, Forsythia suspensa, Salvia miltiorrhiza, Panax pseudoginseng var. notoginseng, and Schisandra chinensis, which provides a reference for the follow-up research of DIR gene.


Asunto(s)
Forsythia , Isatis , Lignanos , Plantas Medicinales , Schisandra , Lignanos/química , Plantas Medicinales/genética , Schisandra/química
17.
Angew Chem Int Ed Engl ; 61(49): e202211490, 2022 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-36128955

RESUMEN

In conventional two-dimensional infrared (2D-IR) spectroscopy, the inherently short vibrational lifetimes limit the time window to observe molecular dynamics typically to tens of picoseconds. The rather complex dynamics of organized molecular systems (e.g., glass formers, polymers, membranes, proteins), however, span a wide range of timescales from femto- to microseconds and beyond. Vibrationally Promoted Electronic Resonance (VIPER) 2D-IR negates the limitations of 2D-IR spectroscopy, for its signal decays with the electronic lifetime. Here, we present 2-Isopropylthioxanthone as the first VIPER 2D-IR probe to exploit intersystem crossing, thereby covering even the microsecond timescale. We achieved the required signal-to-noise ratio and resolution by introducing the Fourier-transform approach to the VIPER 2D-IR pulse sequence. Now, we are in a position to monitor dynamics via spectral diffusion several orders of magnitude beyond the vibrational lifetime of 2D-IR labels.


Asunto(s)
Simulación de Dinámica Molecular , Proteínas , Espectrofotometría Infrarroja/métodos , Proteínas/química , Vibración , Difusión
18.
Neuroradiology ; 63(7): 1071-1078, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33415349

RESUMEN

PURPOSE: Reduced gray-white matter contrast along the central sulcus has been described on T1- and T2-weighted magnetic resonance imaging (MRI). The purpose of this study was to assess the gray-white matter contrast of the motor cortex on double inversion recovery (DIR), a sequence with superior gray-white matter differentiation. METHODS: The gray-white matter signal on DIR was retrospectively compared to T1-weighted magnetization-prepared rapid gradient echo (T1-MPRAGE) using normal (n = 25) and abnormal (n = 25) functional MRI (fMRI) exams. Quantitative gray-white matter contrast ratios (CR) of the precentral and adjacent gyri were obtained on normal exams. Two neuroradiologists qualitatively rated reduced gray-white matter contrast of the hemispheres of both normal and abnormal exams. Hand motor functional mapping was used as a reference. RESULTS: In normal hemispheres (n = 50), the mean CR was significantly lower on DIR (0.44) vs T1-MPRAGE (0.63, p < 0.001). Reduced gray-white matter contrast was categorized as "definitely present" more frequently on DIR than T1-MPRAGE by reviewers in both normal (n = 50; reviewer 1 DIR 88% and MPRAGE 68%, p = 0.02; reviewer 2 DIR 86% and T1-MPRAGE 64%; p=0.01) and abnormal hemispheres (n = 50; reviewer 1 DIR 80% and T1-MPRAGE 38%, p < 0.001; reviewer 2 DIR 74% and T1-MPRAGE 46%, p = 0.005). CONCLUSION: Reduced gray-white matter contrast of the motor cortex is more pronounced on DIR compared to T1-MPRAGE on quantitative and qualitative assessments of normal MRI exams. In abnormal cases, reviewers more definitively identified the motor cortex on DIR. In cases with distorted brain anatomy, DIR may be a useful adjunct sequence to localize the motor cortex.


Asunto(s)
Corteza Motora , Sustancia Blanca , Encéfalo , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Corteza Motora/diagnóstico por imagen , Estudios Retrospectivos , Sustancia Blanca/diagnóstico por imagen
19.
Sensors (Basel) ; 21(22)2021 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-34833827

RESUMEN

Infrared Thermography (IRT) is a non-contact, non-intrusive, and non-ionizing radiation tool used for detecting breast lesions. This paper analyzes the surface temperature distribution (STD) on an optimal Region of Interest (RoI) for extraction of suitable internal heat source parameters. The physiological parameters are estimated through the inverse solution of the bio-heat equation and the STD of suspicious areas related to the hottest spots of the RoI. To reach these values, the STD is analyzed by means: the Depth-Intensity-Radius (D-I-R) measurement model and the fitting method of Lorentz curve. A highly discriminative pattern vector composed of the extracted physiological parameters is proposed to classify normal and abnormal breast thermograms. A well-defined RoI is delimited at a radial distance, determined by the Support Vector Machines (SVM). Nevertheless, this distance is less than or equal to 1.8 cm due to the maximum temperature location close to the boundary image. The methodology is applied to 87 breast thermograms that belong to the Database for Mastology Research with Infrared Image (DMR-IR). This methodology does not apply any image enhancements or normalization of input data. At an optimal position, the three-dimensional scattergrams show a correct separation between normal and abnormal thermograms. In other cases, the feature vectors are highly correlated. According to our experimental results, the proposed pattern vector extracted at optimal position a=1.6 cm reaches the highest sensitivity, specificity, and accuracy. Even more, the proposed technique utilizes a reduced number of physiological parameters to obtain a Correct Rate Classification (CRC) of 100%. The precision assessment confirms the performance superiority of the proposed method compared with other techniques for the breast thermogram classification of the DMR-IR.


Asunto(s)
Neoplasias de la Mama , Termografía , Neoplasias de la Mama/diagnóstico por imagen , Femenino , Calor , Humanos , Aumento de la Imagen , Máquina de Vectores de Soporte , Temperatura
20.
Int J Mol Sci ; 22(23)2021 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-34884871

RESUMEN

Tomato clade species (Solanum sect. Lycopersicon) display multiple interspecific reproductive barriers (IRBs). Some IRBs conform to the SI x SC rule, which describes unilateral incompatibility (UI) where pollen from SC species is rejected on SI species' pistils, but reciprocal pollinations are successful. However, SC x SC UI also exists, offering opportunities to identify factors that contribute to S-RNase-independent IRBs. For instance, SC Solanum pennellii LA0716 pistils only permit SC Solanum lycopersicum pollen tubes to penetrate to the top third of the pistil, while S. pennellii pollen penetrates to S. lycopersicum ovaries. We identified candidate S. pennellii LA0716 pistil barrier genes based on expression profiles and published results. CRISPR/Cas9 mutants were created in eight candidate genes, and mutants were assessed for changes in S. lycopersicum pollen tube growth. Mutants in a gene designated Defective in Induced Resistance 1-like (SpDIR1L), which encodes a small cysteine-rich protein, permitted S. lycopersicum pollen tubes to grow to the bottom third of the style. We show that SpDIR1L protein accumulation correlates with IRB strength and that species with weak or no IRBs toward S. lycopersicum pollen share a 150 bp deletion in the upstream region of SpDIR1L. These results suggest that SpDIR1L contributes to an S-RNase-independent IRB.


Asunto(s)
Proteínas de Plantas/genética , Polen/genética , Solanum lycopersicum/genética , Solanum/genética , Sistemas CRISPR-Cas , Cisteína , Flores/genética , Flores/fisiología , Regulación de la Expresión Génica de las Plantas , Solanum lycopersicum/fisiología , Mutación , Plantas Modificadas Genéticamente , Reproducción/genética , Ribonucleasas/genética , Solanum/fisiología
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