Projected emissions and climate impacts of Arctic shipping along the Northern Sea Route.

The navigability of Arctic maritime passages has improved with the rapid retreat of sea ice in recent decades, and it is projected that the Northern Sea Route (NSR) will support further increases in shipping in the future. However, the opening of the NSR may bring potential environmental and climate risks to the Arctic and the rest of the world. This investigation assessed shipping emissions along the NSR and the climate impacts under global warming of 2 °C and 3 °C to support coordinated international decision-making. The results show that the magnitude of annual energy consumption of ships along the NSR is 109 kWh under global warming of 2 °C and 3 °C. The environmental impacts of the shipping decrease with fuel transition to clean, carbon-neutral fuel sources. Specifically, the maximum emission is CO2 (106 t), followed by NOX (104-5 t), CO (103-4 t), SOX (103 t), CH4 (102-3 t), organic carbon (102-3 t), N2O (101-2 t), and black carbon (BC, 101-2 t), in which CO2 and BC have great difference under high and low loads. Total emission exacerbates Arctic and global warming, and it is more significant in the Arctic in the next twenty years and across the rest of the world in the next one hundred years. The greatest climate impact factor is CO2, followed by NOX and BC which are more important in global and Arctic warming, respectively.

Unraveling the significance of soil organic carbon-gravel parameterization: Insights into soil water and heat transport on the Tibetan Plateau.

In the Tibetan Plateau (TP) soil water and heat transfer process, soil organic carbon (SOC) and gravel content are considered as the most influential soil texture factors. However, the issues of underestimating SOC and neglecting gravel effect affected the simulation performance of CLM5.0 on soil moisture (SM) and soil temperature (ST). This paper proposed a new parameterization scheme, the organic carbon-gravel (OC-G) scheme, to simulate ST and SM from 1990 to 2018. The results showed that correlation between the simulated and observed ST or SM was higher, and the error was smaller, after the modification of the parameterization scheme. This improvement justifies the applicability of the scheme for soil hydrothermal simulations on the TP. The experiment described that ST and SM were more sensitive to changes in SOC content. And changes in gravel or SOC content had the "Same-Frequency" effect in the northeast and southeast TP. When the SOC and gravel content changed at the same time, the effects on ST and SM were a "cumulative" effect. The change directly affected the memory time of ST and SM in summer. Specifically, when the SOC content was increased, the memory time of SM increased in the northwest and decreased in the southeast. When gravel content was increased, the memory time of SM decreased in the northwest but increased in the southeast, but the memory time of ST remained largely unchanged. Changes to the abnormal duration may alter summer weather and climate in Eastern China.

[Research Progressin the Relationship between Interleukin-6 and Intervertebral Disc Degeneration].

Intervertebral disc degeneration (IDD) is one of the main diseases causing low back pain,which seriously affects the quality of life of patients.Recent studies have discovered that interleukin-6 (IL-6) is highly expressed in the tissues and cells of degenerative intervertebral disc and is closely related to the occurrence and development of IDD.However,the signaling pathway and role of IL-6 in IDD remain to be understood.Therefore,this article reviews the recent studies about the signaling pathway and role of IL-6 in IDD,aiming to facilitate the clinical work and subsequent research progress.

What Is the Optimal Timing of Transplantation of Neural Stem Cells in Spinal Cord Injury? A Systematic Review and Network Meta-Analysis Based on Animal Studies.

Objective: The optimal transplantation timing of neural stem cells in spinal cord injury is fully explored in animal studies to reduce the risk of transformation to clinical practice and to provide valuable reference for future animal studies and clinical research. Method: Seven electronic databases, namely, PubMed, Web of Science, Embase, Wanfang, Chinese Scientific Journal Database (CSJD-VIP), China Biomedical Literature Database (CBM), and China National Knowledge Infrastructure (CNKI), were searched. The studies were retrieved from inception to November 2021. Two researchers independently screened the literature, extracted data, and evaluated the methodological quality based on the inclusion criteria. Results and Discussion: Thirty-nine studies were incorporated into the final analyses. Based on the subgroup of animal models and transplantation dose, the results of network meta-analysis showed that the effect of transplantation in the subacute phase might be the best. However, the results of traditional meta-analysis were inconsistent. In the moderate-dose group of moderate spinal cord injury model and the low-dose group of severe spinal cord injury model, transplantation in the subacute phase did not significantly improve motor function. Given the lack of evidence for direct comparison between different transplantation phases, the indirectness of our network meta-analysis, and the low quality of evidence in current animal studies, our confidence in recommending cell transplantation in the subacute phase is limited. In the future, more high-quality, direct comparative studies are needed to explore this issue in depth.

Spinal Cord Injury: A Systematic Review and Network Meta-Analysis of Therapeutic Strategies Based on 15 Types of Stem Cells in Animal Models.

Objective: The optimal therapeutic strategies of stem cells for spinal cord injury (SCI) are fully explored in animal studies to promote the translation of preclinical findings to clinical practice, also to provide guidance for future animal experiments and clinical studies. Methods: PubMed, Web of Science, Embase, CNKI, Wangfang, VIP, and CBM were searched from inception to September 2021. Screening of search results, data extraction, and references quality evaluation were undertaken independently by two reviewers. Results and Discussion: A total of 188 studies were included for data analysis. Results of traditional meta-analysis showed that all 15 diverse types of stem cells could significantly improve locomotor function of animals with SCI, and results of further network meta-analysis showed that adipose-derived mesenchymal stem cells had the greatest therapeutic potential for SCI. Moreover, a higher dose (≥1 × 106) of stem cell transplantation had better therapeutic effect, transplantation in the subacute phase (3-14 days, excluding 3 days) was the optimal timing, and intralesional transplantation was the optimal route. However, the evidence of current animal studies is of limited quality, and more high-quality research is needed to further explore the optimal therapeutic strategies of stem cells, while the design and implementation of experiments, as well as measurement and reporting of results for animal studies, need to be further improved and standardized to reduce the risk when the results of animal studies are translated to the clinic. Systematic Review Registration: [website], identifier [registration number].

Benefits of the Enhanced Recovery After Surgery Program in Short-Segment Posterior Lumbar Interbody Fusion Surgery.

OBJECTIVE: Enhanced recovery after surgery (ERAS) is a multimodal, evidence-based approach to perioperative care that aims to reduce physiological and psychological stress, improve the quality of rehabilitation, and speed up the recovery of patients. Our study aims to investigate the benefits of perioperative use of ERAS for a short-segment posterior lumbar interbody fusion. METHODS: We selected two 1-year periods: the first from before the establishment of the multidisciplinary ERAS team in January 2017 (pre-ERAS year 2016) and the second period when ERAS was applied widely in our hospital (ERAS year 2019). Data were collected from the electronic medical records of patients who had undergone a short-level posterior lumbar interbody fusion during these 2 periods. The primary outcomes were postoperative complications, length of hospital stay, and off-bed time. RESULTS: A total of 207 patients were included; 95 patients in the pre-ERAS group were compared with 112 patients in the ERAS group. There was no significant difference between the 2 groups in baseline demographic. Patients in the ERAS group had significantly shorter length of hospital stay, off-bed time, and earlier drainage tube and catheter removal time. The rate of postoperative complications differed significantly between the pre-ERAS and ERAS groups. Patients in the ERAS group had significantly less intraoperative blood loss, financial cost, and opioid consumption than patients in the pre-ERAS group. The visual analog scale and Oswestry Disability Index scores, similar at baseline, were significantly lower in the ERAS group at postoperative day 3. CONCLUSIONS: The benefits of our ERAS protocol for patients undergoing short-level posterior lumbar fusion are evident in terms of reduced hospital stay and time to get out of bed, reduced incidence of postoperative complications, intraoperative blood loss, opioid use and hospital costs, and improved early postoperative pain and dysfunction.

The Role of Biodegradable Magnesium and Its Alloys in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis Based on Animal Studies.

Objective: The actual efficacy of magnesium and its alloy in anterior cruciate ligament reconstruction (ACLR) was systematically evaluated to reduce the risk of translation from animal experiments to the clinic. Methods: Databases of PubMed, Ovid-Embase, Web of Science, CNKI, Wanfang, VIP, and CBM were searched for literature in July 2021. Screening of search results, data extraction, and literature quality evaluation were undertaken independently by two reviewers. Results and discussion: Seven articles were selected for the meta-analysis. The results showed that the mechanical properties of the femoral-tendon graft-tibia complex fixed with magnesium and its alloys were comparable to those fixed with titanium and its alloys, and magnesium and its alloys were superior to titanium and its alloys in promoting new bone formation. In addition, the unique biodegradability made magnesium and its alloys an orthopedic implant with significant therapeutic potential. However, whether the degradation rate of magnesium and its alloy can match the rate of bone-tendon integration, and whether the bioconjugation of bone-tendon after degradation can meet the exercise load still needs to be explored in further detail. Simultaneously, it is necessary for future research to improve and standardize experimental design, result measurement, etc., so as to minimize the risk of transforming animal experimental results into clinical practice.

Identification of nucleic acid aptamers against lactate dehydrogenase via SELEX and high-throughput sequencing.

Nucleic acid aptamers are small fragments of DNA or RNA molecules binding specifically to targets, which can be obtained through in vitro screening via systematic evolution of ligands by exponential enrichment (SELEX). Lactate dehydrogenase (LDH) is an important tumor marker, whose level in patients is of great significance for diagnosis of many diseases. Here, we report the identification of LDH aptamers by 9 rounds of screening from a length-mixed single-stranded DNA library using the SELEX technology. After the 3rd and 7th rounds of aptamer screening, affinity was significantly improved, and fluorescence quantitative analysis showed stronger affinity for the aptamers selected from the 7th to 9th rounds of screening. After high-throughput sequencing, motif analysis, and secondary structure prediction, we finally chose and further investigated 15 candidate LDH aptamer sequences with obvious differences in secondary structure in the 7th to 9th rounds of screening. Among them, LDH7-1, LDH7-9, LDH8-2, and LDH9-1 were shown to bind to LDH protein with high affinity and specificity with Kd < 25 nM. This study provides new ideas for rapid detection of LDH protein content and enzyme activity, thus contributing to the development of rapid medical detection.

Controllable Self-Assembly of SERS Hotspots in Liquid Environment.

Controllable synthesis of novel metal nanoparticles and effective capture of hotspots are of great significance for SERS (surface-enhanced Raman spectroscopy) detection. Therefore, in this paper, a green controllable synthesis method of gold nanoparticle was achieved via epigallocatechin gallate reduction. Different morphologies of gold nanoparticles were synthesized just by changing the solution pH values, and the growth kinetics of AuNPs (gold nanoparticles) were systematically studied. The synthetic AuNPs were put in a droplet to study dynamic variations of self-assembly SERS hotspots from the liquid sol state to the solid dry state. The addition of halogen ions in the droplet can controllably regulate the self-assembly three-dimensional hotspot model of gold nanoparticles in the evaporation process of a droplet, during which the most enhancement effect can be easily captured. The dynamically changing images of nanoparticles in the process were graphically described based on the internal interaction forces of a droplet. Two stronger areas in the changes of SERS intensity were achieved with a high concentration of halogen ions, while only one maximum intensity area was obtained with a low concentration of halogen ions added. This method can effectively avoid complex and unpredictable microenvironments of SERS substrates in the liquid drop, further improving the reproducibility of SERS detection as well as broadening it to biological applications.

Comparison of the effectiveness of autologous grafts for anterior cruciate ligament reconstruction: A protocol for an overview of systematic review and network meta-analysis.

BACKGROUND: Anterior cruciate ligament rupture is a common motor system injury, and the most effective treatment is anterior cruciate ligament reconstruction (ACLR). Choosing the right graft is an important factor to ensure the success of the surgery. Current research shows that the clinical effect of autologous ligaments is better than that of allogeneic ligaments and artificial ligaments. However, there are differences between the autogenous ligaments, and how to choose them is still controversial. This study evaluated the published systematic reviews on the efficacy of different autologous ligament grafts in ACLR, and based on this, conducted a network meta-analysis of related randomized controlled trials. METHODS: We searched 8 international and Chinese databases including PubMed, Embase, Web of Science, and Cochrane Library. The methodological quality of systematic reviews will be evaluated by Assessing the Methodological Quality of Systematic Reviews-2 (AMSTAR2) measurement tool. Cochrane's risk of bias tool will be used to assess the risk of bias of included randomized controlled trials, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach will be used to evaluate the evidence quality. Network meta-analysis will be applied to evaluate the therapeutic effect of different autologous grafts. The main outcome measures are IKDC score, clinical failure rate, Lachman test, Lysholm score, and the incidence of complications. Odds ratio and its 95% confidence interval will be used to synthesize the dichotomy results, while the mean difference and 95% confidence interval of continuous variables will be used for continuous variables. RESULTS: This study will provide comprehensive evidence for the application of autologous grafts in ACLR. CONCLUSION: The results of this study will help clinicians make appropriate decisions. PROTOCOL REGISTRATION NUMBER: INPLASY202090061.

What factors affect the methodological and reporting quality of clinical practice guidelines for osteoporosis? Protocol for a systematic review.

BACKGROUND: Osteoporosis is a disease with a high prevalence and low treatment rate, which poses a serious threat to the lives of patients and brings a heavy economic burden. Clinical practice guidelines (CPGs) provide vital guidance for disease management. Up to now, different countries, regions, and organizations have issued a certain number of CPGs for osteoporosis, but the recommendations in different guidelines are inconsistent. This protocol plans to evaluate the quality of the CPGs for osteoporosis and then make a comparative analysis of the recommendations in the CPGs. METHODS: Several databases including PubMed, Web of Science, Embase, and Cochrane Library, as well as the official website of relevant organizations will be searched. Screen and data extraction will be performed by two reviewers independently, and the third reviewer help to resolve the divergence between them. Using the AGREE II instrument and RIGHT checklist to assess the methodological and reporting quality of the CPGs. The extracted recommendations, including but not limited to screening, diagnosis, evaluation and treatment, will be summarized and analyzed, and the results will be presented in tabular form. Bubble charts will be used to show quality differences between CPGs and to describe the correlation between methodological and reporting quality through regression analysis. Excel, EndnoteX9 and SPSS 25.0 will be used. RESULT: To evaluate the advantages and disadvantages of the existing CPGs of osteoporosis and analyze the similarities and differences between the recommendations, the results will be published in a peer-reviewed journal. CONCLUSION: This study will provide systematic evidence for existing CPGs of osteoporosis and to provide a reference for CPGs users. PROTOCOL REGISTRATION: INPLASY 202070031.

Transcriptomics Study to Determine the Molecular Mechanism by which sIL-13Rα2-Fc Inhibits Caudal Intervertebral Disc Degeneration in Rats.

BACKGROUND: Intervertebral disc degeneration is related to tissue fibrosis. ADAMTS can degrade the important components of the ECM during the process of intervertebral disc degeneration, ultimately resulting in the loss of intervertebral disc function. sIL-13Rα2-Fc can inhibit fibrosis and slow down the degeneration process, but the mechanism involved remains unclear. OBJECTIVE: To determine the mechanism by which sIL-13Rα2-Fc inhibits ECM degradation and reduces intervertebral disc tissue fibrosis using a transcriptomics analysis. METHODS: A rat model of caudal intervertebral disc degeneration was established, and Sirius red staining was used to observe the pathological changes in the caudal intervertebral disc. Transcriptome sequencing was employed to assess the gene expression profiles of the intervertebral disc tissues in the model group and the sIL-13Rα2-Fc-treated group. Differentially expressed genes were identified and analyzed using GO annotation and KEGG pathway analyses. Real-time fluorescence quantitative PCR was used to verify the expression levels of candidate genes. The levels of GAG and HA were quantitatively assessed by ELISA, and the levels of collagen I and collagen II were analyzed by western blotting. RESULTS: Sirius red staining showed that in the model group, the annulus fibrosus was disordered, the number of breaks increased, and the type I collagen protein levels increased, whereas in the sIL-13Rα2-Fc group, the annulus fibrosus was ordered, the number of breaks decreased, and the type II collagen protein levels increased. In comparison with the model group, we identified 58 differentially expressed genes in the sIL-13Rα2-Fc group, and these were involved in 35 signaling pathways. Compared with those in the model group, the mRNA expression levels of Rnux1, Sod2, and Tnfaip6 in the IL-13Rα2-Fc group were upregulated, and the mRNA expression levels of Aldh3a1, Galnt3, Fgf1, Celsr1, and Adamts8 were downregulated; these results were verified by real-time fluorescence quantitative PCR. TIMP-1 (an ADAMTS inhibitor) and TIMP-1 combined with the sIL-13Rα2-Fc intervention increased the levels of GAG and HA, inhibited the expression of type I collagen, and promoted the expression of type II collagen. CONCLUSION: Adamts8 may participate in the degradation of ECM components such as GAG and HA and lead to an imbalance in the ECM of the intervertebral disc, resulting in intervertebral disc degeneration. sIL-13Rα2-Fc promoted anabolism of the ECM and increased the levels of ECM components by inhibiting the expression of Adamts8, thus maintaining the dynamic equilibrium of the ECM and ultimately delaying intervertebral disc degeneration.

Self-assembled "bridge" substance for organochlorine pesticides detection in solution based on Surface Enhanced Raman Scattering.

Pesticide residues pose a great threat to human health, and it is an urgent matter to realize fast and accurate detection of pesticide. SERS (Surface Enhanced Raman Scattering), as a nondestructive detection technology, performs a prominent role in fast detection field due to the strong surface plasmon resonance from short range effect between analyte and nanoparticle. Therefore, in order to solve the incompatibility between organochlorine pesticides molecules and noble metal nanoparticles, this paper proposed a concept of "bridge" substances acting as an interconnect function role to achieve a binding model (object-binder-metal (OBM)) and developed a droplet concentration method to enhance Raman signals. Both combination mode of pesticide molecules to bridge molecules and energy transfer of SERS experiment may relate to the compound ring according to the changes of peaks based on surface plasmon resonance. The selectivity and stability of different bridge substances interacting with pesticides molecules were illumined via binding energy of these two substances obtained by DFT calculations. A droplet can capture nanoparticles and analytes, which is conducive to SERS performance. Chloride ions in the solution contribute to rearrangement of nanoparticles and can validly promote surface activation of Ag nanoparticles to improve energy transfer efficiency of plasma resonance, resulting in superior SERS effect.

Effect of sIL-13Rα2-Fc on the progression of rat tail intervertebral disc degeneration.

BACKGROUND: The incidence of degenerative disc disease caused by intervertebral disc injury is increasing annually, seriously affecting the quality of life of patients and increasing the disease burden on society. The mechanisms of intervertebral disc degeneration include changes in extracellular matrix (ECM) deposition and tissue fibrosis. sIL-13Rα2-Fc potently inhibits interleukin (IL)-13, as well as blocks related cell signaling pathways and inhibits fibrosis in certain tissues. However, it is unknown whether sIL-13Rα2-Fc inhibits fibrosis in injured intervertebral discs and slows the process of degeneration. We hypothesized that sIL-13Rα2-Fc delays the progression of intervertebral disc degeneration by inhibiting intervertebral disc fibrosis and improving ECM deposition. METHODS: A rat tail intervertebral disc degeneration model was established. Pathological changes in rat intervertebral disc tissue were observed by hematoxylin and eosin staining and Masson staining. Glycosaminoglycan (GAG), chondroitin sulfate (CS), keratan sulfate (KS), and hyaluronic acid (HA) contents were quantitatively analyzed by enzyme-linked immunosorbent assay. Type I and type II collagen expression levels were analyzed by reverse transcription-PCR and western blotting. RESULTS: Hematoxylin and eosin staining and Masson staining revealed annulus fibrosus rupture, disordered arrangement, decreased nucleus pulposus tissue, and decreased collagen fiber in the rat intervertebral disc tissue. Following treatment with sIL-13Rα2-Fc, pathological changes in the rat intervertebral disc were reduced. Rat intervertebral disc tissue showed decreased GAG, CS-KS, and (HA) contents, increased type I collagen levels, and decreased type II collagen levels in degenerated intervertebral discs. sIL-13Rα2-Fc intervention increased the contents of GAG, CS, KS, and HA; inhibited the expression of type I collagen; and promoted the expression of type II collagen. CONCLUSION: These results demonstrate that intervertebral disc degeneration is associated with tissue fibrosis. sIL-13Rα2-Fc can regulate type I and type II collagen expression levels by increasing GAG, CS, KS, and HA contents, thereby slowing the progression of intervertebral disc degeneration.

Towards a Stable and High-Performance Hindered Phenol/Polymer-Based Damping Material Through Structure Optimization and Damping Mechanism Revelation.

Although hindered phenol/polymer-based hybrid damping materials, with excellent damping performance, attract more and more attention, the poor stability of hindered phenol limits the application of such promising materials. To solve this problem, a linear hindered phenol with amorphous state and low polarity was synthesized and related polyurethane-based hybrid materials were prepared in this study. The structure and state of the hindered phenol were confirmed by nuclear magnetic resonance spectrum, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The existence of intermolecular hydrogen bonds (HBs) between hindered phenol and polyurethane was confirmed by FT-IR, and the amorphous state of the hybrids was confirmed by XRD. Moreover, by a combination of molecular dynamics simulation and dynamic mechanical analysis, the relationship between the structure optimization of the hindered phenol and the high damping performance of the hybrids was quantitatively revealed. By constructing the synthetic hindered phenol, the intramolecular HBs between hindered phenols were restricted, while the strength and concentration of the intermolecular HBs increased by increasing the amount of hindered phenol. Thus, intermolecular interactions were enhanced, which lead to the compact chain packing of polyurethane, extended chain packing of hindered phenol, and good dispersion of hindered phenol in polyurethane. Therefore, the stability of the hindered phenol and the damping properties of the hybrids were both improved. The experiment results are expected to provide some useful information for the design and fabrication of high-performance polymeric damping materials.

A heterobimetallic metal-organic framework as a "turn-on" sensor toward DMF.

A non-luminescent 3d-4f heterobimetallic CuEu organic framework (NBU-8) was designedly synthesized with Cu2+ ions as a fluorescence quencher. NBU-8 as a sensor realized selective light recovery with a "turn-on" luminescence response toward N,N'-dimethylformamide (DMF) even in the presence of other amide molecules.

Global registration of subway tunnel point clouds using an augmented extended Kalman filter and central-axis constraint.

Because tunnels generally have tubular shapes, the distribution of tie points between adjacent scans is usually limited to a narrow region, which makes the problem of registration error accumulation inevitable. In this paper, a global registration method is proposed based on an augmented extended Kalman filter and a central-axis constraint. The point cloud registration is regarded as a stochastic system, and the global registration is considered to be a process that recursively estimates the rigid transformation parameters between each pair of adjacent scans. Therefore, the augmented extended Kalman filter (AEKF) is used to accurately estimate the rigid transformation parameters by eliminating the error accumulation caused by the pair-wise registration. Moreover, because the scanning range of a terrestrial laser scanner can reach hundreds of meters, a single scan can cover a tunnel segment with a length of more than one hundred meters, which means that the central axis extracted from the scan can be employed to control the registration of multiple scans. Therefore, the central axis of the subway tunnel is first determined through the 2D projection of the tunnel point cloud and curve fitting using the RANSAC (RANdom SAmple Consensus) algorithm. Because the extraction of the central axis by quadratic curve fitting may suffer from noise in the tunnel points and from variations in the tunnel, we present a global extraction algorithm that is based on segment-wise quadratic curve fitting. We then derive the central-axis constraint as an additional observation model of AEKF to optimize the registration parameters between each pair of adjacent scans. The proposed approach is tested on terrestrial point clouds that were acquired in a subway tunnel. The results show that the proposed algorithm is capable of improving the accuracy of aligning multiple scans by 48%.

Fast response and highly selective sensing of amine vapors using a luminescent coordination polymer.

Detecting volatile amines is a significant topic in the quality control of food and medical diagnosis. We report the first Eu-coordination polymer (CP) as a sensory material for the detection of a class of amine vapors with high selectivity and rapid response.

3-Fold-interpenetrated uranium-organic frameworks: new strategy for rationally constructing three-dimensional uranyl organic materials.

The first series of 3-fold-interpenetrated uranium-organic frameworks, UOF-1 and UOF-2, have been synthesized by hydrothermal reactions of flexible semirigid carboxylic acids and uranyl nitrate. Structure analyses indicate that UOF-1 and UOF-2 possess flu and pts topologies, respectively.

Synthesis of N-(2-pyridyl)indoles via Pd(II)-catalyzed oxidative coupling.

Readily available Pd(II) chloride catalysts can catalyze selective and efficient oxidative coupling between N-aryl-2-aminopyridines and internal alkynes to yield N-(2-pyridyl)indoles. This process involves the ortho C-H activation of N-aryl-2-aminopyridines, and CuCl(2) was used as an oxidant. Compared to our previously reported Rh(III)-catalyzed synthesis of this class of product, this method is advantageous with a wider scope of alkynes and cost-effective Pd(II) catalysts. Molecular oxygen can be used as a terminal oxidant.