An in-depth analysis of postoperative insomnia in elderly patients and its implications on rehabilitation.

OBJECTIVES: (1) Assess the prevalence of postoperative insomnia; (2) identify the risk factors for postoperative insomnia before exposure to surgery; (3) explore the impact of postoperative insomnia on rehabilitation. METHODS: A study was conducted with 132 participants aged ≥ 65 undergoing spine interbody fusion. We collected the basic demographic data, Numeric Rating Scales (NRS), Pittsburgh Sleep Quality Index (PSQI), Geriatric Depression Scale (GDS), and Beck Anxiety Inventory (BAI). We measured Quality of Recovery 40 (QoR-40), GDS, BAI, NRS, and PSQI on the first and third nights post-surgery, followed by QoR-40 and NRS assessments two weeks after surgery. RESULTS: The cases of postoperative insomnia on the first and third nights and after two weeks were 81 (61.36%), 72 (54.55%), and 64 (48.48%), respectively, and the type of insomnia was not significantly different (P = 0.138). Sleep efficiency on the first night was 49.96% ± 23.51. On the first night of postoperative insomnia, 54 (66.67%) cases were depression or anxiety, and the PSQI was higher in this group than in the group without anxiety or depression (P < 0.001). PSQI, GDS, and the time of surgery were related factors for postoperative insomnia (PPSQI < 0.001, PGDS = 0.008, and PTime = 0.040). Postoperative rehabilitation showed differences between the insomnia and non-insomnia groups (P < 0.001). CONCLUSIONS: The prevalence of postoperative insomnia in the elderly was high, and postoperative insomnia had a significant correlation with postoperative rehabilitation. Interventions that target risk factors may reduce the prevalence of postoperative insomnia and warrant further research. CLINICAL TRIAL REGISTRATION: Multivariate analysis of postoperative insomnia in elderly patients with spinal surgery and its correlation with postoperative rehabilitation ( https://www.chictr.org.cn/bin/project/edit?pid=170201 ; #ChiCTR2200059827).

Deep profiling of potential substrate atlas of porcine epidemic diarrhea virus 3C-like protease.

Coronavirus (CoV) 3C-like protease (3CLpro) is essential for viral replication and is involved in immune escape by proteolyzing host proteins. Deep profiling the 3CLpro substrates in the host proteome extends our understanding of viral pathogenesis and facilitates antiviral drug discovery. Here, 3CLpro from porcine epidemic diarrhea virus (PEDV), an enteropathogenic CoV, was used as a model which to identify the potential 3CLpro cleavage motifs in all porcine proteins. We characterized the selectivity of PEDV 3CLpro at sites P5-P4'. We then compiled the 3CLpro substrate preferences into a position-specific scoring matrix and developed a 3CLpro profiling strategy to delineate the protein substrate landscape of CoV 3CLpro. We identified 1,398 potential targets in the porcine proteome containing at least one putative cleavage site and experimentally validated the reliability of the substrate degradome. The PEDV 3CLpro-targeted pathways are involved in mRNA processing, translation, and key effectors of autophagy and the immune system. We also demonstrated that PEDV 3CLpro suppresses the type 1 interferon (IFN-I) cascade via the proteolysis of multiple signaling adaptors in the retinoic acid-inducible gene I (RIG-I) signaling pathway. Our composite method is reproducible and accurate, with an unprecedented depth of coverage for substrate motifs. The 3CLpro substrate degradome establishes a comprehensive substrate atlas that will accelerate the investigation of CoV pathogenicity and the development of anti-CoV drugs.IMPORTANCECoronaviruses (CoVs) are major pathogens that infect humans and animals. The 3C-like protease (3CLpro) encoded by CoV not only cleaves the CoV polyproteins but also degrades host proteins and is considered an attractive target for the development of anti-CoV drugs. However, the comprehensive characterization of an atlas of CoV 3CLpro substrates is a long-standing challenge. Using porcine epidemic diarrhea virus (PEDV) 3CLpro as a model, we developed a method that accurately predicts the substrates of 3CLpro and comprehensively maps the substrate degradome of PEDV 3CLpro. Interestingly, we found that 3CLpro may simultaneously degrade multiple molecules responsible for a specific function. For instance, it cleaves at least four adaptors in the RIG-I signaling pathway to suppress type 1 interferon production. These findings highlight the complexity of the 3CLpro substrate degradome and provide new insights to facilitate the development of anti-CoV drugs.

Automatic segmentation of white matter hyperintensities and correlation analysis for cerebral small vessel disease.

Objective: Cerebral white matter hyperintensity can lead to cerebral small vessel disease, MRI images in the brain are used to assess the degree of pathological changes in white matter regions. In this paper, we propose a framework for automatic 3D segmentation of brain white matter hyperintensity based on MRI images to address the problems of low accuracy and segmentation inhomogeneity in 3D segmentation. We explored correlation analyses of cognitive assessment parameters and multiple comparison analyses to investigate differences in brain white matter hyperintensity volume among three cognitive states, Dementia, MCI and NCI. The study explored the correlation between cognitive assessment coefficients and brain white matter hyperintensity volume. Methods: This paper proposes an automatic 3D segmentation framework for white matter hyperintensity using a deep multi-mapping encoder-decoder structure. The method introduces a 3D residual mapping structure for the encoder and decoder. Multi-layer Cross-connected Residual Mapping Module (MCRCM) is proposed in the encoding stage to enhance the expressiveness of model and perception of detailed features. Spatial Attention Weighted Enhanced Supervision Module (SAWESM) is proposed in the decoding stage to adjust the supervision strategy through a spatial attention weighting mechanism. This helps guide the decoder to perform feature reconstruction and detail recovery more effectively. Result: Experimental data was obtained from a privately owned independent brain white matter dataset. The results of the automatic 3D segmentation framework showed a higher segmentation accuracy compared to nnunet and nnunet-resnet, with a p-value of <0.001 for the two cognitive assessment parameters MMSE and MoCA. This indicates that larger brain white matter are associated with lower scores of MMSE and MoCA, which in turn indicates poorer cognitive function. The order of volume size of white matter hyperintensity in the three groups of cognitive states is dementia, MCI and NCI, respectively. Conclusion: The paper proposes an automatic 3D segmentation framework for brain white matter that achieves high-precision segmentation. The experimental results show that larger volumes of segmented regions have a negative correlation with lower scoring coefficients of MMSE and MoCA. This correlation analysis provides promising treatment prospects for the treatment of cerebral small vessel diseases in the brain through 3D segmentation analysis of brain white matter. The differences in the volume of white matter hyperintensity regions in subjects with three different cognitive states can help to better understand the mechanism of cognitive decline in clinical research.

Automatic Localization of Key Structures for Subthalamic Nucleus-Deep Brain Stimulation Surgery via Prior-Enhanced Multi-Object Magnetic Resonance Imaging Segmentation.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established and effective neurosurgical treatment for relieving motor symptoms in Parkinson disease. The localization of key brain structures is critical to the success of DBS surgery. However, in clinical practice, this process is heavily dependent on the radiologist's experience. METHODS: In this study, we propose an automatic localization method of key structures for STN-DBS surgery via prior-enhanced multi-object magnetic resonance imaging segmentation. We use the U-Net architecture for the multi-object segmentation, including STN, red nucleus, brain sulci, gyri, and ventricles. To address the challenge that only half of the brain sulci and gyri locate in the upper area, potentially causing interference in the lower area, we perform region of interest detection and ensemble joint processing to enhance the segmentation performance of brain sulci and gyri. RESULTS: We evaluate the segmentation accuracy by comparing our method with other state-of-the-art machine learning segmentation methods. The experimental results show that our approach outperforms state-of-the-art methods in terms of segmentation performance. Moreover, our method provides effective visualization of key brain structures from a clinical application perspective and can reduce the segmentation time compared with manual delineation. CONCLUSIONS: Our proposed method uses deep learning to achieve accurate segmentation of the key structures more quickly than and with comparable accuracy to human manual segmentation. Our method has the potential to improve the efficiency of surgical planning for STN-DBS.

Enhancing the depth perception of DSA images with 2D-3D registration.

Objective: Today, cerebrovascular disease has become an important health hazard. Therefore, it is necessary to perform a more accurate and less time-consuming registration of preoperative three-dimensional (3D) images and intraoperative two-dimensional (2D) projection images which is very important for conducting cerebrovascular disease interventions. The 2D-3D registration method proposed in this study is designed to solve the problems of long registration time and large registration errors in 3D computed tomography angiography (CTA) images and 2D digital subtraction angiography (DSA) images. Methods: To make a more comprehensive and active diagnosis, treatment and surgery plan for patients with cerebrovascular diseases, we propose a weighted similarity measure function, the normalized mutual information-gradient difference (NMG), which can evaluate the 2D-3D registration results. Then, using a multi-resolution fusion optimization strategy, the multi-resolution fused regular step gradient descent optimization (MR-RSGD) method is presented to attain the optimal value of the registration results in the process of the optimization algorithm. Result: In this study, we adopt two datasets of the brain vessels to validate and obtain similarity metric values which are 0.0037 and 0.0003, respectively. Using the registration method proposed in this study, the time taken for the experiment was calculated to be 56.55s and 50.8070s, respectively, for the two sets of data. The results show that the registration methods proposed in this study are both better than the Normalized Mutual (NM) and Normalized Mutual Information (NMI). Conclusion: The experimental results in this study show that in the 2D-3D registration process, to evaluate the registration results more accurately, we can use the similarity metric function containing the image gray information and spatial information. To improve the efficiency of the registration process, we can choose the algorithm with gradient optimization strategy. Our method has great potential to be applied in practical interventional treatment for intuitive 3D navigation.

Targeting LRRC41 as a potential therapeutic approach for hepatocellular carcinoma.

Introduction: Hepatocellular carcinoma (HCC) is the most common primary liver cancer, characterized by high mortality rate. In clinical practice, several makers of liver cancer, such as VEGFR1, FGFR1 and PDGFRα, were identified and their potentials as a therapeutic target were explored. However, the unsatisfied treatment results emphasized the needs of new therapeutic targets. Methods: 112 HCC patients samples were obtained to evaluate the expression of LRRC41, SOX9, CD44, and EPCAM in HCC, combined with prognosis analysis. A DEN-induced HCC rat model was constructed to verify the expression of LRRC41 and SOX9 in HCC and lung metastasis tissues. Immune score evaluation was analysized by bioinformatics methods. Network pharmacology was performed to explored the potential FDA-approved drugs targeting LRRC41. Results: Through analysis of the Timer database and tissue micro-array, we confirmed that LRRC41 was over-expressed in HCC and exhibited a significant positive correlation with recurrence and metastasis. Immunohistochemistry staining of human HCC tissue samples revealed significant upregulation of LRRC41, SOX9, CD44, and EPCAM, with LRRC41 showing a positive correlation with SOX9, CD44, and EPCAM expression. UALCAN database analysis indicated that LRRC41 and SOX9 contribute to poor prognosis whereas CD44 and EPCAM did not demonstrate the same significance. Furthermore, analysis of a DEN-induced HCC rat model confirmed the significantly elevated expression of LRRC41 and SOX9 in HCC and lung metastasis tissues. Drug sensitivity analysis and molecular docking targeting LRRC41 identified several FDA-approved drugs, which may have potential antitumor effects on HCC by targeting LRRC41. Conclusion: Our findings highlight the role of LRRC41 overexpression in promoting HCC progression and its association with a poor prognosis. Drug sensitivity analysis and molecular docking shows several FDA-approved drugs may be potential therapeutic targets for HCC. Targeting LRRC41 may hold promise as a potential therapeutic strategy for HCC.

Experimental Study on the Slip Behaviour of Stainless Steel High-Strength Bolted Connections with a New Surface Treatment.

The conventional surface treatments on stainless steel plates yield slip factors less than the required value for a friction grip, which hinders the application of stainless steel high-strength bolts. The slip factor and the treatment process of stainless steel surfaces are not clearly specified in most of the existing design codes. Existing studies also show different slip factors from similarly treated surfaces. In this paper, a new surface treatment is proposed: the two touching surfaces of the bolted connection are grit-blasted on one side and coated with high-velocity oxygen fuel (HVOF) on the other side. The slip behaviour of the new method was compared with four conventional methods. The roughness and hardness of different surfaces were measured prior to a total of 30 slip tests where the slip factors of multiple stainless steel surfaces were tested. It was shown that the new proposed surface treatment method can yield a slip factor of 0.61, much higher than the conventional surface treatments, meeting the requirements as a slip-resistant connection. The preload relaxation of stainless steel high-strength bolts was also monitored and compared to standard grade 10.9 high-strength bolts. We found that the preload relaxation in stainless steel high-strength bolts is negligible.

Simultaneous optimization of ultrasound-assisted extraction for total flavonoid content and antioxidant activity of the tender stem of Triarrhena lutarioriparia using response surface methodology.

The asparagus of Triarrhena lutarioriparia (TL) is a popular vegetable with abundant chemical compounds in China. This study aims to optimize the ultrasound-assisted extraction (UAE) method for its content of total flavonoid and antioxidant activities by response surface methodology (RSM). Box-Behnken design was adopted to evaluate the influences of ethanol concentration, extraction time and solvent-to-sample ratio on the extraction yield of total flavonoid and the antioxidant activity. Considering the maximum content of extracted total flavonoids and antioxidant activity, the optimal extraction conditions were acquired with 70% (v/v) ethanol by UAE for 60 min at a solvent-to-sample ratio of 40 mL/g. The proportion of the extraction of total flavonoid was 15.88 mg/g and antioxidant activity reached 79.53%. The RSM would be recommended as an appropriate model for simultaneous optimization of the UAE conditions for the content of total flavonoid and the antioxidant activity of asparagus of TL.

A brain somatic RHEB doublet mutation causes focal cortical dysplasia type II.

Focal cortical dysplasia type II (FCDII) is a cerebral cortex malformation characterized by local cortical structure disorganization, neuronal dysmorphology, and refractory epilepsy. Brain somatic mutations in several genes involved in the PI3K/AKT/mTOR pathway are associated with FCDII, but they are only found in a proportion of patients with FCDII. The genetic causes underlying the development FCDII in other patients remain unclear. Here, we carried out whole exome sequencing and targeted sequencing in paired brain-blood DNA from patients with FCDII and identified a brain somatic doublet mutation c.(A104T, C105A) in the Ras homolog, mTORC1 binding (RHEB) gene, which led to the RHEB p.Y35L mutation in one patient with FCDII. This RHEB mutation carrier had a dramatic increase of ribosomal protein S6 phosphorylation, indicating mTOR activation in the region of the brain lesion. The RHEB p.Y35L mutant protein had increased GTPλS-binding activity compared with wild-type RHEB. Overexpression of the RHEB p.Y35L variant in cultured cells also resulted in elevated S6 phosphorylation compared to wild-type RHEB. Importantly, in utero electroporation of the RHEB p.Y35L variant in mice induced S6 phosphorylation, cytomegalic neurons, dysregulated neuron migration, abnormal electroencephalogram, and seizures, all of which are found in patients with FCDII. Rapamycin treatment rescued abnormal electroencephalograms and alleviated seizures in these mice. These results demonstrate that brain somatic mutations in RHEB are also responsible for the pathogenesis of FCDII, indicating that aberrant activation of mTOR signaling is a primary driver and potential drug target for FCDII.

Dexmedetomidine alleviates cerebral ischemia-reperfusion injury in rats via inhibition of hypoxia-inducible factor-1α.

Dexmedetomidine (Dex) was reported to reduce ischemia-reperfusion (I/R) injury in kidney and brain tissues. Thus, we aimed to study the role and mechanism of Dex in cerebral I/R injury by inhibiting hypoxia-inducible factor-1α (HIF-1α) and apoptosis. First, I/R injury models were established. Six groups were assigned after different treatments: sham, I/R, I/R+Dex, I/R+2-methoxyestradiol (2ME2) (HIF-1α inhibitor), I/R+CoCl 2 (HIF-1α activator), and I/R+Dex+CoCl 2 groups. Neurological function, cerebral infarction volume, survival, and apoptosis of brain cells were then analyzed. Besides, immunohistochemistry and Western blot analysis were used to detect the expression of HIF-1α, BCL-2[B-cell leukemia/lymphoma 2] adenovirus E1B interacting protein 3 (BNIP3), B-cell leukemia/lymphoma 2 (BCL2), BCL2[B-cell leukemia/lymphoma 2] associated X (Bax), and cleaved-caspase3 proteins in brain tissues. I/R rats showed cerebral infarction, increased neurological function score, number of terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL)-positive cells and HIF-1α-positive cells as well as decreased neurons. Inhibition of HIF-1α can reduce the apoptosis induced by I/R, and overexpression of HIF-1α can aggravate apoptosis in brain tissue of I/R rats. Furthermore, activation of HIF-1α expression blocks the inhibitory effect of Dex on neuronal apoptosis in I/R rats. Dex may inhibit the neuronal apoptosis of I/R rats by inhibiting the HIF-1α pathway and then improve the cerebral I/R injury in rats.

Composition of The Essential Oil From Danggui-zhiqiao Herb-Pair and Its Analgesic Activity and Effect on Hemorheology in Rats With Blood Stasis Syndrome.

BACKGROUND: Angelica sinensis and Aurantii fructu used in a pair, named Danggui-Zhiqiao herb-pair (DZHP), which was rich in essential oil and has been adopted to promote blood circulation, dispel blood stasis, and relieve pain in traditional Chinese medicine (TCM). OBJECTIVE: To analyze the composition and pharmacological effects of essential oil from DZHP. MATERIALS AND METHODS: The composition of the essential oil from DZHP was analyzed by gas chromatography/mass spectrometry (GC/MS). Its analgesic activity was evaluated by acetic acid-induced writhing test and hot plate test. The hemorheology test was carried out to evaluate the effect on hemorheology in rats with blood stasis syndrome. RESULTS: Twenty-eight components were identified and the main components were α-pinene (3.07%), ß-pinene (2.0%), ß-myrcene (3.71%), D-limonene (49.28%), γ-terpinen (9.53%), α-terpinolene (1.80%), α-terpineol (2.02%), ß-bisabolene (1.13%), butylidenephthalide (1.43%), and Z-ligustilide (16.08%). The pharmacology test showed that the essential oil significantly inhibited the number of writhes induced by acetic acid with inhibition rate of 44.64% and significantly increased hot-plate latency compared with control group from 30 to 90 min after oral administration of drugs in mice. It could significantly decrease plasma viscosity, whole blood relative index at high and low shear rate, whole blood reduced viscosity at high and low shear rate, and erythrocyte rigidity index in hemorheology test. CONCLUSION: The composition of the essential oil of DZHP was determined successfully and it had analgesic and promoting blood circulation activities. SUMMARY: Angelica sinensis and Aurantii fructu used in a pair, named Danggui-Zhiqiao herb-pair (DZHP), which was rich in Essential oil and has been adopted to promote blood circulation, dispel blood stasis and relieve pain in traditional Chinese medicine (TCM).Twenty-eight components were identified and the main components were α-pinene (3.07%), ß-pinene (2.0%), ß-myrcene (3.71%), D-limonene (49.28%), γ-terpinen (9.53%), α-terpinolene (1.80%), α-terpineol (2.02%), ß-bisabolene (1.13%), butylidenephthalide (1.43%), and Z-ligustilide (16.08%).The essential oil significantly inhibited the number of writhes induced by acetic acid and increased hot-plate latency compared with control group from 30 min to 90 min after oral administration of drugs in mice.The essential oil could significantly decrease plasma viscosity (PV), whole blood relative index (WBRI) at high and low shear rate, whole blood reduced viscosity (WBRV) at high and low shear rate, and erythrocyte rigidity index (ERI) in hemorheology test. Abbreviations used: DZHP: Danggui-Zhiqiao herb-pair; TCM: traditional Chinese medicine; GC/MS: gas chromatography /mass spectrometry; PV: plasma viscosity; WBRI: whole blood relative index; WBRV: whole blood reduced viscosity; ERI: erythrocyte rigidity index.

Successful surgery in lesional epilepsy secondary to posterior quandrant ulegyria coexisting with benign childhood focal epilepsy: A case report.

The present study reports, for the first time, a rare case of benign childhood focal epilepsy(BCFE) coexisting with lesional epilepsy secondary to parietooccipital ulegyria. The patient underwent right parietooccipital lobe disconnection plus tailored resection of temporooccipitoparietal junction cortex under electrocorticography (ECoG) monitoring. Post-operatively, there was no impairment of neurological function and the patient only experiences a few breakthrough benign partial seizures during sleep.

Analysis of Rayleigh-Brillouin spectral profiles and Brillouin shifts in nitrogen gas and air.

On the basis of experimental Rayleigh-Brillouin scattering data in gaseous nitrogen and air, simulations are performed to describe the observed frequency profiles in analytical form. The experimental data pertain to a λ = 366 nm scattering wavelength, a 90° scattering angle, pressures of 1 and 3 bar, and temperatures in the range 250 - 340 K. Two different models are used to represent the RB-profiles, to distinguish the RB-peaks, and to obtain the Brillouin shift associated with the acoustic waves generated in a gaseous medium. Calculations in the framework of V3 and G3 models, exhibiting composite profiles of three distinct peaks of Voigt or Gaussian functions, are compared to observation. Fitting results show that the V3 model yields an improvement over the G3 model. This mathematical model provides an even better representation of the observed profiles than the Tenti S6 model, which is considered to be the optimum representation in terms of physical parameters. For the derivation of Brillouin shifts, both models perform well at high gas pressure, while at lower pressures, the V3 model yields a higher accuracy than the G3 model.

[Study on material basis of essential oil from Yin Teng Gu Bi Kang prescription on activating blood circulation].

OBJECTIVE: To explore the component difference of the serum containing essential oil from Yin Teng Gu Bi Kang prescription in pathologic and physiologic rat models, and to reveal the material basis of its efficacy of activating blood circulation. METHODS: The essential oils were obtained by CO2 supercritical fluid extraction and the ingredients of the essential oils in vitro and in vivo (under physiological and pathological status) were analyzed by GC-MS to compare differences of the essential oil under physiological and pathological status in rats. RESULTS: 32 components were identified with the main components of Z-ligustilide (39.23%) and d-limonene (21.7%) in the essential oil. In vivo analysis on the essential oil indicated that 16 components were identified, 7 existed originally in essential oil and 9 were metabolites under physiological status; while 22 components were identified, 10 existed originally in essential oil and 12 were metabolites under pathological status (acute blood stasis). There were 7 common prototypes and 8 common metabolites under different physiological status. CONCLUSION: The absorption and metabolism of essential oils were affected by blood stasis and the compounds migrating to blood may be the effective substance in activating blood circulation.

TAP-binding peptides prediction by QSAR modeling based on amino acid structural information.

The transporter associated with antigen processing (TAP) is essential for peptide delivery from the cytosol into the lumen of the endoplasmic reticulum (ER), where these peptides are loaded on a major histocompatibility complex (MHC) I molecules and form peptide-MHC complex. The peptide-MHC leaves the ER and displays their antigenic cargo on the cell surface to cytotoxic T cells. In this study, 89 physicochemical properties of amino acid were collected from AAIndex database, and used to characterize the peptides which were binding to TAP. Then, the stepwise regression (STR) was used to optimize the parameters which characterized the TAP binding peptides, and the multiple linear regression (MLR) was used to construct the quantitative structural activity relationship (QSAR) model based on optimized parameters. The quantitative models had good reliability and predictive ability: the Q² of "leave one out" validation is 0.676 and R² of test dataset is 0.722 respectively. Additionally, the standardized coefficients of the models could demonstrate the attributions for each position of epitope and determine which special amino acid is suitable at any position of the peptide. Therefore, the QSAR model constructed by STR-MLR has many advantages, such as, easier calculation and explanation, good performance, and definite physiochemical indication, which could be used to guide the design and modification of the TAP binding peptide.

Inhibitory effect of organic carbon on CO2 fixing by non-photosynthetic microbial community isolated from the ocean.

The inhibitory effect of organic carbon on CO(2) fixation (CF) by the non-photosynthetic microbial community (NPMC) and its mechanism were studied. The results showed that different concentrations of glucose inhibited CF to some extent. However, when these microorganisms pre-cultured with glucose were re-cultured without organic carbon, their CF efficiency differed significantly from the control based on the glucose concentration in the pre-culture. ATP as bioenergy and NADH as reductant had no obvious inhibitory effect on CF; conversely, they improved CF efficiency to some extent, especially when both were present simultaneously. These results implied that not all organic materials inhibited CF by NPMC, and only those that acted as good carbon sources, such as glucose, inhibited CF. Moreover, some metabolites generated during the catabolism of glucose by heterotrophic metabolism of NPMC might inhibit CF, while other cumulated materials present in the cell interior, such as ATP and NADH, might improve CF.

A new tarkadectine primate from the Eocene of Inner Mongolia, China: phylogenetic and biogeographic implications.

Tarka and Tarkadectes are Middle Eocene mammals known only from the Rocky Mountains region of North America. Previous work has suggested that they are members of the Plagiomenidae, an extinct family often included in the order Dermoptera. Here we describe a new primate, Tarkops mckennai gen. et sp. nov., from the early Middle Eocene Irdinmanha Formation of Inner Mongolia, China. The new taxon is particularly similar to Tarka and Tarkadectes, but it also displays many features observed in omomyids. A phylogenetic analysis based on a data matrix including 59 taxa and 444 dental characters suggests that Tarkops, Tarka and Tarkadectes form a monophyletic group--the Tarkadectinae--that is nested within the omomyid clade. Within Omomyidae, tarkadectines appear to be closely related to Macrotarsius. Dermoptera, including extant and extinct flying lemurs and plagiomenids, is recognized as a clade nesting within the polyphyletic group of plesiadapiforms, therefore supporting the previous suggestion that the relationship between dermopterans and primates is as close as that between plesiadapiforms and primates. The distribution of tarkadectine primates on both sides of the Pacific Ocean basin suggests that palaeoenvironmental conditions appropriate to sustain primates occurred across a vast expanse of Asia and North America during the Middle Eocene.