Echo-Level SAR Imaging Simulation of Wakes Excited by a Submerged Body.

The paper introduces a numerical simulation method for Synthetic Aperture Radar (SAR) imaging of submerged body wakes by integrating hydrodynamics, electromagnetic scattering, and SAR imaging simulation. This work is helpful for better understanding SAR images of submerged body wakes. Among these, the hydrodynamic model consists of two sets of ocean dynamics closely related to SAR imaging, namely the wake of the submerged body and wind waves. For the wake, we simulated it using computational fluid dynamics (CFD) numerical methods. Furthermore, we compared and computed the electromagnetic scattering characteristics of wakes under various navigation parameters and sea surface conditions. Following that, based on the operational principles and imaging theory of synthetic aperture radar (SAR), we established the SAR raw echo signal of the wake. Employing a Range-Doppler (RD) algorithm, we generated simulated SAR images of the wake. The results indicate that utilizing Computational Fluid Dynamics (CFD) numerical methods enables the simulation of wake characteristics generated by the motion of a submerged body with different velocities. The backscattering features of wakes are closely associated with the relative orientation between the wake and the radar line of sight. Under specific wind speeds, the wake gets masked within the sea surface background, resulting in less discernible characteristics of the wake in SAR images. This suggests that at lower speeds of submerged body or under specific wind conditions, the detectability of the wake in SAR images significantly diminishes.

Wiring Covalent Organic Frameworks with Conducting Polymers.

Covalent organic frameworks are a class of crystalline porous polymers formed by linking organic units into periodically aligned skeletons and pores. Here we report a strategy for wiring these frameworks with conducting polymers via wall engineering and polymerization. We anchored each edge site with one pyrrole unit, which is densely packed along the z direction yet protruded from pore walls. This assembly enables the polymerization of pyrrole units to form polypyrrole and creates a new polypyrrole chain conformation. The resultant framework constitutes six single file polypyrrole chains in each pore and develop spatially segregated yet built-in single molecular wires with exceptional stable polarons. Hall effect measurements revealed that the materials are p-type semiconductors, increase conductivity by eight orders of magnitude compared to the pristine frameworks, and achieve a carrier mobility as large as 13.2 cm2 V-1 s-1. Our results open an avenue to π electronic frameworks by interlayer molecular wiring with conducting polymers.

Beam quality control technology for solid-state lasers based on thermal effects.

Thermal effects under high-power pumping significantly limit the laser beam quality. To address this, we developed an M2 simulation algorithm based on ray trajectory simulation and established a corresponding experimental platform. This approach optimized the M2 factor of pulsed lasers to 2.2 and output power of 25.9 W under a repetition rate of 10 kHz. The results revealed that under specific conditions, thermal effects, typically considered detrimental to beam quality, could significantly enhance it. Compared to other methods necessitating additional optical components, our strategy offers a streamlined and straightforward solution for beam quality control under high-power pumping conditions.

Covalent Organic Frameworks: Design, Synthesis, and Functions.

Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers with permanent porosity and highly ordered structures. Unlike other polymers, a significant feature of COFs is that they are structurally predesignable, synthetically controllable, and functionally manageable. In principle, the topological design diagram offers geometric guidance for the structural tiling of extended porous polygons, and the polycondensation reactions provide synthetic ways to construct the predesigned primary and high-order structures. Progress over the past decade in the chemistry of these two aspects undoubtedly established the base of the COF field. By virtue of the availability of organic units and the diversity of topologies and linkages, COFs have emerged as a new field of organic materials that offer a powerful molecular platform for complex structural design and tailor-made functional development. Here we target a comprehensive review of the COF field, provide a historic overview of the chemistry of the COF field, survey the advances in the topology design and synthetic reactions, illustrate the structural features and diversities, scrutinize the development and potential of various functions through elucidating structure-function correlations based on interactions with photons, electrons, holes, spins, ions, and molecules, discuss the key fundamental and challenging issues that need to be addressed, and predict the future directions from chemistry, physics, and materials perspectives.

Covalent organic frameworks: an ideal platform for designing ordered materials and advanced applications.

Covalent organic frameworks offer a molecular platform for integrating organic units into periodically ordered yet extended two- and three-dimensional polymers to create topologically well-defined polygonal lattices and built-in discrete micropores and/or mesopores. This polymer architecture is unique as it enables predesigning both primary- and high-order structures, greatly enhancing our capabilities of designing organic materials to produce predictable structures and to achieve unique properties and functions. Progress over the past 15 years in the design, synthesis and functional exploration of COFs has successively established the basis of the COF field and COFs have shown the great potential of chemistry in developing a class of amazing organic materials. In this review, we focus on analysing the historic developments of COFs to uncover a full materials and application picture by providing comprehensive yet clear guidance for molecular design, synthetic control and functional exploration. We scrutinise the structural components of COFs including building blocks, reactive sites and functional groups with the aim of finding the origins of structural designability and diversity, as well as multiple functionalities. We disclose strategies for designing and synthesising frameworks to construct various tailor-made interfaces, and for exploring skeletons and pores to design properties and functions. With well-defined skeletons, pores and interfaces that offer a chemical basis to trigger and control interactions with photons, excitons, phonons, polarons, electrons, holes, spins, ions and molecules, we illustrate the current status of our understandings of structure-property correlations, and unveil the principles for establishing a regime to design unique functions that originate from and are inherent to structures. We predict the key central issues in design and synthesis, the challenges in functional design and the future directions from the perspectives of chemistry, physics and materials science.

Covalent Organic Frameworks: Pore Design and Interface Engineering.

Nature evolves fascinating molecular pores to achieve unique biological functions based on a single pore or channel as observed for aquaporins and ion channels. An artificial system, on the other hand, explores porous structures to construct dense pores in materials. Progress in chemistry over the past century has greatly improved our capability to synthesize porous materials. This is evident by the advancement from inorganic to organic units, from trial-and-error tests to module fabrication and further to fully predesignable pores, and from harsh preparation protocols to ambient synthetic methods. Over the past 15 years, a molecular platform based on organic and polymer chemistry has been explored to enable the design of artificial pores to achieve different pore size, shape, wall, and interface. This becomes possible with a class of emerging polymer-covalent organic frameworks (COFs). COFs are a class of crystalline porous polymers that integrate organic units into extended molecular frameworks with periodically ordered skeletons and well-defined pores. We have focused on exploring COFs over the past 15 years to design and synthesize porous structures with the aim of developing chemistry that leads to the creation of tailor-made pore interfaces (Nagai, A. et al. Nat. Commun., 2011, 2, 536). In this Account, we summarize the general concept of our approaches to various pore interfaces by emphasizing design principle, synthetic strategy, and distinct porous features and their impacts. We illustrate pore interface design by highlighting general strategies based on direct polymerization and pore surface engineering to construct different pore walls with a diversity of functional units. One distinct feature is that these functional groups are predesigned and synthetically controlled to achieve a predetermined component, position, and density, leading to a general way to install various specific pore wall interfaces to each pore. We showcase hierarchical pore interface architectures by elucidating the nature of interplays between interfaces and molecules and ions, ranging broadly from hydrogen bond to dipole-dipole/quadrupole interactions, electrostatic interaction, acid-base interaction, coordination, and electronic interactions. We scrutinize the unique properties and functions of adsorption and separation, catalysis, energy transformation and storage, and proton and metal ion transport by disclosing functional design schemes and interface-function correlations. We predict the fundamental key issues to be addressed and show future directions in designing artificial pores to target at ultimate functions. This chemistry on pore interface engineering opens a way to porous materials that have remained challenging in the predesign of both structure and function.

Rigid Polymer Network-Based Autonomous Photoswitches Working in the Solid State Encoded by Room-Temperature Phosphorescence.

Autonomous molecular switches with self-recoverability are of great theoretical and experimental interest since they can avoid additional chemical or energy imposition during the working process. Due to the high energy barrier, however, the solid state is generally unfavorable for materials to exhibit the autonomous switch behavior. To promote the practical usage of the autonomous molecular switch, herein, we propose a prototype of an autonomous photoswitch that can work in the solid state based on a rigid polymer network. A hexacarboxylic sodium-modified hexathiobenzene compound was employed as a photoexcitation-driven unit, which can undergo molecular aggregation upon irradiation because of the distinct conformational difference between the ground state and the photoexcited state. Then, we selected a relatively rigid polymer named poly(dimethyldiallylammonium)chloride (PDDA) to complex with the hexacarboxylic sodium-modified hexathiobenzene through electrostatic coupling. Through optimization, the photoexcitation-controlled molecular aggregation and its self-recovery can work well in the solid matrix of PDDA under rhythmical photoirradiation. This process can be easily encoded by a self-recoverable room-temperature phosphorescence, featuring an excellent performance of the autonomous switch.

CO2 introduced the coagulation-flocculation of oil acidized wastewater: pollutant removal and cost analysis.

It is difficult to adjust the pH of oil acidized wastewater rich in Ca2+, thus hindering the polyacrylamide (PAM) flocculation. This study aims at accelerating the flocculation process by introducing CO2 into the water to induce the formation of CaCO3 nuclei. The order in which CO2 and NaOH were added affected the floc structures. Compared with CO2-NaOH-PAM, the flocs of NaOH-CO2-PAM were more compact and more CaCO3 crystals were formed. The aqueous Ca2+ involved in the reaction reached 20%, and CO2 utilization was enhanced. The settling time was shortened by half (from 20 to 3 min), and NaOH consumption was reduced by one-tenth (from 0.03 to 0.003 mol), hence significantly reducing the costs. Due to the higher settling rate and shorter contact time, the NaOH-CO2-PAM flocs adsorbed less so that the residual oil was 124 mg·L-1, while in the case of CO2-NaOH-PAM it was 88 mg·L-1. As a promising coagulation aid, CO2 can also be used to mineralize pollutants in wastewater.

Covalent Organic Frameworks: Chemical Approaches to Designer Structures and Built-In Functions.

A new approach has been developed to design organic polymers using topology diagrams. This strategy enables covalent integration of organic units into ordered topologies and creates a new polymer form, that is, covalent organic frameworks. This is a breakthrough in chemistry because it sets a molecular platform for synthesizing polymers with predesignable primary and high-order structures, which has been a central aim for over a century but unattainable with traditional design principles. This new field has its own features that are distinct from conventional polymers. This Review summarizes the fundamentals as well as major progress by focusing on the chemistry used to design structures, including the principles, synthetic strategies, and control methods. We scrutinize built-in functions that are specific to the structures by revealing various interplays and mechanisms involved in the expression of function. We propose major fundamental issues to be addressed in chemistry as well as future directions from physics, materials, and application perspectives.

Crystal Multi-Conformational Control Through Deformable Carbon-Sulfur Bond for Singlet-Triplet Emissive Tuning.

Crystal-state luminophores have been of great interest in optoelectronics for years, whereas the excited state regulation at the crystal level is still restricted by the lack of control ways. We report that the singlet-triplet emissive property can be profoundly regulated by crystal conformational distortions. Employing fluoro-substituted tetrakis(arylthio)benzene luminophores as prototype, we found that couples of molecular conformations formed during different crystallizations. The deformable carbon-sulphur bond essentially drove the distortion of the molecular conformation and varied the stacking mode, together with diverse non-covalent interactions, leading to the proportional adjustment of the fluorescence and phosphorescence bands. This intrinsic strategy was further applied for solid-state multicolor emissive conversion and mechanoluminescence, probably offering new insights for design of smart crystal luminescent materials.

Spontaneous Glutamatergic Synaptic Activity Regulates Constitutive COX-2 Expression in Neurons: OPPOSING ROLES FOR THE TRANSCRIPTION FACTORS CREB (cAMP RESPONSE ELEMENT BINDING) PROTEIN AND Sp1 (STIMULATORY PROTEIN-1).

Burgeoning evidence supports a role for cyclooxygenase metabolites in regulating membrane excitability in various forms of synaptic plasticity. Two cyclooxygenases, COX-1 and COX-2, catalyze the initial step in the metabolism of arachidonic acid to prostaglandins. COX-2 is generally considered inducible, but in glutamatergic neurons in some brain regions, including the cerebral cortex, it is constitutively expressed. However, the transcriptional mechanisms by which this occurs have not been elucidated. Here, we used quantitative PCR and also analyzed reporter gene expression in a mouse line carrying a construct consisting of a portion of the proximal promoter region of the mouse COX-2 gene upstream of luciferase cDNA to characterize COX-2 basal transcriptional regulation in cortical neurons. Extracts from the whole brain and from the cerebral cortex, hippocampus, and olfactory bulbs exhibited high luciferase activity. Moreover, constitutive COX-2 expression and luciferase activity were detected in cortical neurons, but not in cortical astrocytes, cultured from wild-type and transgenic mice, respectively. Constitutive COX-2 expression depended on spontaneous but not evoked excitatory synaptic activity and was shown to be N-methyl-d-aspartate receptor-dependent. Constitutive promoter activity was reduced in neurons transfected with a dominant-negative cAMP response element binding protein (CREB) and was eliminated by mutating the CRE-binding site on the COX-2 promoter. However, mutation of the stimulatory protein-1 (Sp1)-binding site resulted in an N-methyl-d-aspartate receptor-dependent enhancement of COX-2 promoter activity. Basal binding of the transcription factors CREB and Sp1 to the native neuronal COX-2 promoter was confirmed. In toto, our data suggest that spontaneous glutamatergic synaptic activity regulates constitutive neuronal COX-2 expression via Sp1 and CREB protein-dependent transcriptional mechanisms.

A Cucurbit[7]uril Based Molecular Shuttle Encoded by Visible Room-Temperature Phosphorescence.

A visible room-temperature phosphorescence (RTP) signal, generated by complexation of cururbit[7]uril (CB[7]) and bromo-substituted isoquinoline in aqueous solution, is employed to address the shuttling of a pH-controlling molecular shuttle fabricated by CB[7] and a phosphor 6-bromoisoquinoline derivative IQC[5]. The CB[7] host shuttles along the axial guest under acidic conditions, accompanied by a weak RTP emission signal, while deprotonation of the guest IQC[5] makes the CB[7] wheel locate on the phosphor group, leading to intense RTP emission. The switching RTP emission of the molecular shuttle, via pH adjusting, can be visibly identified by the naked eye. This is the first CB-based molecular shuttle with an RTP signal as the output address of its shuttling and conformation.

The trends and hotspots of immunotherapy for metastatic colorectal cancer from 2013 to 2022: A bibliometric and visual analysis.

An increasing body of research indicates that immunotherapy has demonstrated substantial effectiveness in the realm of metastatic colorectal cancer(mCRC), especially among patients with deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-H) (dMMR/MSI-H mCRC). This study constitutes the inaugural bibliometric and visual analysis of immunotherapy related to mCRC during the last decade. Between 2013 and the conclusion of 2022, we screened 306 articles from Web of Science and subjected them to analysis using CiteSpace and VOSviewer. The United States stood out as the primary contributor in this area, representing 33.33% of the publications, with China following closely at 24.51%. The most prolific institution has the lowest average citation rate. Sorbonne University were the most highly cited institutions. Notably, Frontiers In Oncology published the largest quantity of articles. Andre, Thierry, and Overman, Michael J. were prominent authors known for their prolific output and the high citation rates of their work. The focus areas in this field encompass "tumor microenvironment," "liver metastasis," "tumor-associated macrophages," "combination therapy" and "gut microbiota." Some keywords offer promise as potential biomarkers for evaluating the effectiveness of immunotherapeutic interventions.

Clinical value of the Patient Global Assessment with Ankylosing Spondylitis: A cross-sectional study.

To analyze the factors associated with the overall patient condition and explore the clinical value of the Patient Global Assessment (PGA) index for assessing the disease state in patients with Ankylosing Spondylitis (AS). This cross-sectional study used a standardized questionnaire to record the basic information of patients with AS. The collected data included the Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP), ASDAS-erythrocyte sedimentation rate (ESR), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), PGA, and other clinical indicators. Statistical analysis was performed using SPSS 25.0 software, and the scale was assessed for retest reliability and structural validity. The Kruskal-Wallis H test and Spearman or Pearson correlation analysis were used to analyze the factors influencing PGA scores. The receiver operator characteristic (ROC) curve was used to identify the cutoff value of the PGA for predicting disease activity in AS. The patient age, disease duration, family history, and history of ocular inflammation significantly differed between PGA groups (P < .05). The median PGA was significantly lower in patients with disease remission than in those with disease activity (P < .01). The various clinical indexes significantly differed between PGA groups (P < .01). The PGA was significantly correlated with various clinical indicators (P < .01). The area under the ROC curve (AUC) for disease activity based on the ASDAS-CRP was 0.743 (P < .01) with a PGA cutoff value of 1.38; the AUC for disease activity based on the BASDAI was 0.715 (P < .01) with a PGA cutoff value of 1.63. The PGA was significantly correlated with patient-reported outcomes, disease activity, function, and psychological status, and may indicate the level of inflammation in patients with AS. A PGA of around 1.5 indicates disease activity.

Foxg1 has an essential role in postnatal development of the dentate gyrus.

Foxg1, formerly BF-1, is expressed continuously in the postnatal and adult hippocampal dentate gyrus (DG). This transcription factor (TF) is thought to be involved in Rett syndrome, which is characterized by reduced hippocampus size, indicating its important role in hippocampal development. Due to the perinatal death of Foxg1(-/-) mice, the function of Foxg1 in postnatal DG neurogenesis remains to be explored. Here, we describe the generation of a Foxg1(fl/fl) mouse line. Foxg1 was conditionally ablated from the DG during prenatal and postnatal development by crossing this line with a Frizzled9-CreER(TM) line and inducing recombination with tamoxifen. In this study, we first show that disruption of Foxg1 results in the loss of the subgranular zone and a severely disrupted secondary radial glial scaffold, leading to the impaired migration of granule cells. Moreover, detailed analysis reveals that Foxg1 may be necessary for the maintenance of the DG progenitor pool and that the lack of Foxg1 promotes both gliogenesis and neurogenesis. We additionally show that Foxg1 may be required for the survival and maturation of postmitotic neurons and that Foxg1 may be involved in Reelin signaling in regulating postnatal DG development. Last, prenatal deletion of Foxg1 suggests that it is rarely involved in the migration of primordial granule cells. In summary, we report that Foxg1 is critical for DG formation, especially during early postnatal stage.

Synchronal pulmonary sarcomatoid carcinoma and lung adenocarcinoma EML4-ALK fusion: A case report.

Pulmonary sarcomatoid carcinoma (PSC) is a rare form of poorly differentiated non-small-cell lung cancer that is prone to distant metastases. PSC is therapeutically challenging, with low sensitivity to conventional radiotherapy and a poor overall prognosis. The present study reported on the case of a 29-year-old male non-smoker diagnosed with both PSC and lung adenocarcinoma; the cancer had a complex etiology and rapidly metastasized after surgery. The patient presented with an EML4-ALK gene fusion in both tumors with high programmed death ligand-1 (PD-L1) expression. After initial treatment failure, Alectinib, Anlotinib and Tirelizumab were combined, which rapidly resolved the patient's symptoms and led to partial remission of disease at 6 weeks and effective control of the disease 7 months into the treatment. This case exemplifies the efficacy of combining targeted chemotherapy with immunotherapy for patients with PSC. Furthermore, this outcome suggests the usefulness of genetic testing and monitoring PD-L1 expression to identify patients with PSC who may be candidates likely to respond to this combined therapeutic regimen. The present study provides evidence of the success of a novel therapeutic strategy for patients with PSC.

Appropriate empirical antifungal therapy is associated with a reduced mortality rate in intensive care unit patients with invasive fungal infection: A real-world retrospective study based on the MIMIC-IV database.

Objective: The study aimed to determine the prevalence and pathogens of invasive fungal infection (IFI) among intensive care unit (ICU) patients. The next goal was to investigate the association between empirical antifungal treatment and mortality in ICU patients. Methods: Using microbiological events, we identified all ICU patients with IFI and then retrieved electronic clinical data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The data were statistically analyzed using t-tests, chi-square tests, log-rank tests, and Cox regression. Results: The most commonly reported fungi were Candida (72.64%) and Aspergillus (19.08%). The most frequently prescribed antifungal medication was fluconazole (37.57%), followed by micafungin (26.47%). In the survival study of ICU patients and patients with sepsis, survivors were more likely to receive empirical antifungal treatment. In contrast, non-empirical antifungal therapy was significantly associated with poor survival in patients with positive blood cultures. We found that the current predictive score makes an accurate prediction of patients with fungal infections challenging. Conclusions: Our study demonstrated that empirical antifungal treatment is associated with decreased mortality in ICU patients. To avoid treatment delays, novel diagnostic techniques should be implemented in the clinic. Until such tests are available, appropriate empirical antifungal therapy could be administered based on a model that predicts the optimal time to initiate antifungal therapy. Additional studies should be conducted to establish more accurate predictive models in the future.

Thrombocytopenia in 737 adult intensive care unit patients: A real-world study of associated factors, drugs, platelet transfusion, and clinical outcome.

OBJECTIVE: We aimed to identify and represent factors associated with thrombocytopenia in intensive care unit, especially the pathogens and drugs related to severe and extremely thrombocytopenia. Then, we aim to compare the mortality of platelet transfusion and non-transfusion in patients with different degrees of thrombocytopenia. METHODS: We identified all thrombocytopenic patients in intensive care unit by using platelet-specific values and then extracted electronic health records from our Hospital Information System. Data were statistically analyzed with t test, chi-square test, and logistic regression. RESULTS: We found that infections (32.7%) were the most frequent cause associated with thrombocytopenia, followed by sepsis shock (3.93%) and blood loss (2.99%). Meanwhile, antifungals (p = 0.002) and bacterial infection (p = 0.037) were associated with severe and extremely severe thrombocytopenia. Finally, we found that the mortality of platelet transfusion and non-transfusion in patients was statistically significant for patients with platelet counts between 30 and 49/nL (χ2 = 9.719, p = 0.002). CONCLUSION: Infection and sepsis emerged as two primary factors associated with thrombocytopenia in intensive care unit. Meanwhile, antifungals and bacterial infection were associated with platelet counts less than 49/nL. Finally, platelet transfusion may be associated with reduced mortality in patients with platelet counts between 30 and 49/nL.

The reduction of Cr(VI) to Cr(III) mediated by environmentally relevant carboxylic acids: State-of-the-art and perspectives.

The detoxification process mediated by carboxylic acids (CAs) has received considerable spotlights since CAs are clean reagent and ubiquitous in the natural environments and effluents. Here, we present an exhaustive review on surface-bound/dissolved metals-catalyzed Cr(VI) reduction by CAs and CAs-mediated Cr(VI) reduction by many highly/poorly reductive reagents. The overall mechanisms of Cr(VI) reduction are mainly associated with the coordination of CAs with surface-bound/dissolved metals or Cr(VI,V,IV) species and the electron donating abilities of CAs. Additionally, the general decays of intermediate Cr(V,IV) complexes are clearly emerged in the Cr(VI) reduction processes. The performance of various reaction systems for Cr(VI) reduction that is greatly dependent on the operation parameters, including solution pH, reagent concentration, temperature, coexisting ions and gas atmosphere, are also critically commented. From the study survey presented herein, CAs-mediated Cr(VI) reduction processes exhibit good potential for remediation of various Cr(VI)-contaminated waters/sites. However, there is still a need to address the remained bottle-necks and challenges for the remediation of Cr(VI) mediated by CAs in the related natural attenuation cases and the treatment of industrial effluents. Overall, the present review offers the comprehensive understanding of the Cr(VI) reduction mediated by CAs and provide the engineering community with the guidelines for Cr(VI) remediation in the real-world applications.

Effects of stand age on carbon storage in dragon spruce forest ecosystems in the upper reaches of the Bailongjiang River basin, China.

At an ecosystem level, stand age has a significant influence on carbon storage (CS). Dragon spruce (Picea asperata Mast.) situated along the upper reaches of the Bailongjiang River in northwest China were categorized into three age classes (29-32 years, Y1; 34-39 years, Y2; 40-46 years, Y3), and age-related differences in total carbon storage (TCS) of the forest ecosystem were investigated for the first time. Results showed that TCS for the Y1, Y2, and the Y3 age groups were 323.64, 240.66 and 174.60 Mg ha-1, respectively. The average TCS of the three age groups was 255.65 Mg C ha-1, with above-ground biomass, below-ground biomass, litter, and soil in the top 0.6 m contributing 15.0%, 3.7%, 12.1%, and 69.2%, respectively. CS in soil and TCS of the Y1 age group both significantly exceeded those of the Y3 age group (P < 0.05). Contrary to other recent findings, the present study supports the hypothesis that TCS is likely to decrease as stand age increases. This indicates that natural resource managers should rejuvenate forests by routinely thinning older stands, thereby not only achieving vegetation restoration, but also allowing these stands to create a long-term carbon sink for this important eco-region.