Structure-activity relationship between gold nanoclusters and human serum albumin: Effects of ligand isomerization.

The interactions between gold nanoclusters (AuNCs) and proteins have been extensively investigated. Nevertheless, the structure-activity relationship between gold nanoclusters and proteins in terms of ligand isomerization remained unclear. Here, interactions between Au25NCs modified with para-, inter- and ortho-mercaptobenzoic acid (p/m/o-MBA-Au25NCs) and human serum albumin (HSA) were analyzed. The results of the multispectral approach showed that all three gold nanoclusters bound to the site I in dynamic modes to increase the stability of HSA. There were significant differences in the binding intensity, thermodynamic parameters, main driving forces, and binding ratios between these three gold nanoclusters and HSA, which might be related to the existence forms of the three ligands on the surface of AuNCs. Due to the different polarities of AuNCs themselves, the impact of three AuNCs on the microenvironment of amino acid residues in HSA was also different. It could be seen that ligand isomerization significantly affected the interactions between gold nanoclusters and proteins. This work will provide theoretical guidance for ligand selection and biological applications of metal nanoclusters.

Angular-Momentum Transfer Mediated by a Vibronic-Bound-State.

The notion that phonons can carry pseudo-angular momentum has many major consequences, including topologically protected phonon chirality, Berry curvature of phonon band structure, and the phonon Hall effect. When a phonon is resonantly coupled to an orbital state split by its crystal field environment, a so-called vibronic bound state forms. Here, a vibronic bound state is observed in NaYbSe2 , a quantum spin liquid candidate. In addition, field and polarization dependent Raman microscopy is used to probe an angular momentum transfer of ΔJz = ±â„ between phonons and the crystalline electric field mediated by the vibronic bound stat. This angular momentum transfer between electronic and lattice subsystems provides new pathways for selective optical addressability of phononic angular momentum via electronic ancillary states.

Monolayer Superconductivity and Tunable Topological Electronic Structure at the Fe(Te,Se)/Bi2 Te3 Interface.

The interface between 2D topological Dirac states and an s-wave superconductor is expected to support Majorana-bound states (MBS) that can be used for quantum computing applications. Realizing these novel states of matter and their applications requires control over superconductivity and spin-orbit coupling to achieve spin-momentum-locked topological interface states (TIS) which are simultaneously superconducting. While signatures of MBS have been observed in the magnetic vortex cores of bulk FeTe0.55 Se0.45 , inhomogeneity and disorder from doping make these signatures unclear and inconsistent between vortices. Here superconductivity is reported in monolayer (ML) FeTe1-y Sey (Fe(Te,Se)) grown on Bi2 Te3 by molecular beam epitaxy (MBE). Spin and angle-resolved photoemission spectroscopy (SARPES) directly resolve the interfacial spin and electronic structure of Fe(Te,Se)/Bi2 Te3 heterostructures. For y = 0.25, the Fe(Te,Se) electronic structure is found to overlap with the Bi2 Te3 TIS and the desired spin-momentum locking is not observed. In contrast, for y = 0.1, reduced inhomogeneity measured by scanning tunneling microscopy (STM) and a smaller Fe(Te,Se) Fermi surface with clear spin-momentum locking in the topological states are found. Hence, it is demonstrated that the Fe(Te,Se)/Bi2 Te3 system is a highly tunable platform for realizing MBS where reduced doping can improve characteristics important for Majorana interrogation and potential applications.

Effects of placenta previa on surgical and pregnancy outcomes in patients with total/subtotal or segmental hysterectomy attributed to placenta accreta spectrum disorders / 中华围产医学杂志

Objective:To investigate the effects of placenta previa on the surgical and pregnancy outcomes in patients with total/subtotal or segmental hysterectomy attributed to placenta accreta spectrum disorders (PAS).Methods:This study retrospectively enrolled 510 patients who gave birth and underwent total/subtotal hysterectomy or segmental hysterectomy (local implantation site) due to PAS at the third Affiliated Hospital of Guangzhou Medical University from January 1, 2017, to December 31, 2022. These subjects were divided into the placenta previa group (427 cases) and non-placenta previa group (83 cases). According to the type of hysterectomy, they were further divided into the total/subtotal hysterectomy and placenta previa subgroup (221 cases), total/subtotal hysterectomy and non-placenta previa subgroup (23 cases), segmental hysterectomy and placenta previa subgroup (206 cases), and segmental hysterectomy and non-placenta previa subgroup (60 cases). Nonparametric test or Chi-square test were used to compare the differences in the clinical features, surgical and pregnancy outcomes between different groups. Binary logistic regression was used to analyze the effects of placenta previa on the risk of additional surgical procedures and adverse maternal outcomes. Results:(1) Compared with the non-placenta previa group, the hemorrhage volume within 24 h postpartum [1 541 ml (1 036-2 368 ml) vs 1 111 ml (695-2 000 ml), Z=－3.91] and the proportion of women requiring additional surgical procedures [84.8% (362/427) vs 69.9% (58/83), χ2=10.61], with total/subtotal hysterectomy [51.8% (221/427) vs 27.7% (23/83), χ2=16.10], cystoscopy and/or ureteral stenting [60.7% (259/427) vs 31.3% (26/83), χ2=24.25], total adverse pregnancy outcomes [86.9% (371/427) vs 65.1% (54/83), χ2=17.75], hemorrhage volume>1 500 ml within 24 h postpartum [54.1% (231/427) vs 33.7% (28/83), χ2=29.94], transfusion of blood products [75.9% (324/427) vs 47.0% (39/83), χ2=28.27] were all higher in the placenta previa group (all P<0.05). Binary logistic regression analysis found that for PAS patients with hysterectomy, regardless of the hysterectomy type (total/subtotal/segmental), placenta previa was risk factor for requiring additional surgical procedures ( aOR=3.26, 95% CI: 1.85-5.72) and adverse pregnancy outcomes ( aOR=5.59, 95% CI: 2.01-6.42), even if adjusting for the confounding factors such as maternal age, number of previous cesarean sections, parity, gestational weight gain, twin pregnancy, and the use of assisted reproductive technology. (2) In patients with total/subtotal hysterectomy, the proportion of women requiring additional surgical procedures was higher in those with placenta previa [82.8% (183/221) vs 56.5% (13/23), χ2=9.11] than those without placenta previa, especially the proportion of cystoscopy and/or ureteral stenting [67.9% (150/221) vs 34.8% (8/23), χ2=9.99] (both P<0.05). However, no significant difference was found in adverse pregnancy outcomes [89.6% (198/221) vs 87.0% (20/23), χ2<0.01, P=0.972] between the two groups. In patients with segmental hysterectomy, higher proportions of women requiring additional surgery [86.9% (179/206) vs 75.0% (45/60), χ2=4.94], with adverse pregnancy outcomes [84.0% (173/206) vs 56.7% (34/60), χ2=25.31], cystoscopy and/or ureteral stenting [52.9% (109/206) vs 30.0% (18/60), χ2=9.78], vascular occlusion [94.2% (194/206) vs 71.7% (43/60), χ2=24.23], hemorrhage volume>1 500 ml within 24 h postpartum [46.6% (96/206) vs 23.3% (14/60), χ2=10.37], and transfusion of blood products [68.9% (142/206) vs 33.3% (20/60), χ2=24.73] were found in the placenta previa group (all P<0.05). Furthermore, patients with placenta previa had more hemorrhage volume within 24 h postpartum [1 368 ml (970-2 026 ml) vs 995 ml (654-1 352 ml), Z=－3.66, P<0.001] in the segmental hysterectomy subgroup. After adjusting for the confounding factors such as age, number of previous cesarean sections, parity, gestational weight gain, twin pregnancy, and the use of assisted reproductive technology, binary logistic regression analysis found that placenta previa did not increase the risk of additional surgical operations ( aOR=2.71, 95% CI: 0.99-7.42) and adverse pregnancy outcomes ( aOR=2.14, 95% CI: 0.54-8.42) in patients with total/subtotal hysterectomy but were risk factors of the two outcomes for those with segmental hysterectomy ( aOR=4.67, 95% CI: 2.15-10.10; aOR=3.80, 95% CI: 1.86-7.77). Conclusions:Placenta previa increases the risk of additional surgical procedures and adverse pregnancy outcomes in patients with total/subtotal or segmental hysterectomy caused by PAS. Appropriate preparation is required after the clinical diagnosis of PAS with placenta previa.

Numerical simulation and parameter optimization of earth auger in hilly area using EDEM software.

Digging in hilly regions is an important measure to promote afforestation on difficult sites. In view of the working conditions to build fish-scale pit on slope, the auger mechanism of soil lifting and throwing was investigated in this study. This study utilized EDEM software to establish the operation model of the earth auger and conduct DEM (Discrete Element Method) virtual simulation experiments. A quadratic rotating orthogonal center combination test was implemented by setting the efficiency of conveying-soil (Y1) and the distance of throwing-soil (Y2) as the evaluation indices. Variance analysis and response surface optimization were performed on the virtual experimental data. The results indicated that the weight of the factors affecting the Y1 and Y2, were feeding speed > helix angle > rotating speed > slope angle, and slope auger > rotating speed > feeding speed > helix angle. The optimal parameter combination of each influencing factor was obtained. Among them, when the slope preparation was required, the optimal operating parameter combination of the auger was: Slope of 26.467°, Helix angle of 21.567°, Feeding speed of 0.1 m/s, Rotating speed of 67.408 r/min. This research provides theoretical references for the design optimization of the earth auger in hilly regions.

Correlated oxide Dirac semimetal in the extreme quantum limit.

Quantum materials (QMs) with strong correlation and nontrivial topology are indispensable to next-generation information and computing technologies. Exploitation of topological band structure is an ideal starting point to realize correlated topological QMs. Here, we report that strain-induced symmetry modification in correlated oxide SrNbO3 thin films creates an emerging topological band structure. Dirac electrons in strained SrNbO3 films reveal ultrahigh mobility (µmax ≈ 100,000 cm2/Vs), exceptionally small effective mass (m* ~ 0.04me), and nonzero Berry phase. Strained SrNbO3 films reach the extreme quantum limit, exhibiting a sign of fractional occupation of Landau levels and giant mass enhancement. Our results suggest that symmetry-modified SrNbO3 is a rare example of correlated oxide Dirac semimetals, in which strong correlation of Dirac electrons leads to the realization of a novel correlated topological QM.

The complete chloroplast genome sequence of Pennisetum flaccidum (Poaceae).

Pennisetum flaccidum Grisebach is a typical high-quality forage and adrought-tolerant grass. In this study, we firstly reported the complete chloroplast (cp) genome of P. flaccidum, which was 138,336 bp in length, including a pair of inverted repeats (IR: 22,293 bp), a large single copy (LSC: 81,329 bp), and a small single copy (SSC: 12,421 bp) region. A total of 131 genes were annotated, containing seven rRNA genes, 38 tRNA genes, and 86 protein-coding genes. The GC content of the cp genome was 38.63%. The maximum-likelihood (ML) phylogenetic tree indicated that P. flaccidum was closely related to P. cetaceum in Poaceae.

Laser-induced transient magnons in Sr3Ir2O7 throughout the Brillouin zone.

Although ultrafast manipulation of magnetism holds great promise for new physical phenomena and applications, targeting specific states is held back by our limited understanding of how magnetic correlations evolve on ultrafast timescales. Using ultrafast resonant inelastic X-ray scattering we demonstrate that femtosecond laser pulses can excite transient magnons at large wavevectors in gapped antiferromagnets and that they persist for several picoseconds, which is opposite to what is observed in nearly gapless magnets. Our work suggests that materials with isotropic magnetic interactions are preferred to achieve rapid manipulation of magnetism.

Role of mitochondrial fusion and fission in protective effects of dexmedetomidine against cerebral ischemia/reperfusion injury in mice / 南方医科大学学报

OBJECTIVE@#To investigate the protective effects of dexmedetomidine (DEX) against cerebral ischemia/reperfusion (I/R) injury in mice and its relation with mitochondrial fusion and fission.@*METHODS@#Male ICR mice were randomly divided into sham-operated group, I/R group, I/R+DEX group and I/R+DEX+dorsomorphin group. Mouse models of cerebral I/R injury were established by modified thread occlusion of the middle cerebral artery. DEX (50 μg/kg) was injected intraperitoneally at 30 min before cerebral ischemia, which lasted for 1 h followed by reperfusion for 24 h. The neurobehavioral deficits of the mice were evaluated based on Longa's scores. The volume of cerebral infarction was detected by TTC staining. The changes in mitochondrial morphology of the brain cells were observed with transmission electron microscopy. Western blotting was performed to detect the expressions of phosphorylated AMP-activated protein kinase (p-AMPK), mitochondrial fusion protein (Mfn2) and mitochondrial fission protein (p-Drp1) in the brain tissues.@*RESULTS@#DEX pretreatment significantly reduced the neurobehavioral score and the percent volume of cerebral infarction in mice with cerebral I/R injury. Treatment with dorsomorphin (an AMPK inhibitor) in addition to DEX significantly increased the neurobehavioral score and the percent volume of cerebral infarction in the mouse models. Transmission electron microscopy showed that DEX obviously reduced mitochondrial damage caused by cerebral I/R injury and restored mitochondrial morphology of the brain cells, and such effects were abolished by dorsomorphin treatment. Western blotting showed that DEX pretreatment significantly increased the expressions of p-AMPK and Mfn2 protein and decreased the expression of p-Drp1 protein in the brain tissue of the mice, and these changes were also reversed by dorsomorphin treatment.@*CONCLUSIONS@#Preconditioning with DEX produces protective effects against cerebral I/R injury in mice possibly by activating AMPK signaling to regulate mitochondrial fusion and fission in the brain cells.

Down-regulation of pannexin 2 channel enhances cisplatin-induced apoptosis in testicular cancer I-10 cells / 南方医科大学学报

OBJECTIVE@#To investigate the effect of down-regulation of pannexin 2 (Panx-2) channels on cisplatin-induced apoptosis in I-10 cells.@*METHODS@#The expression of Panx-2 protein in testicular cancer cells was detected with Western blotting. The testicular cancer cell line I-10 was transfected with two short hairpin RNA (shRNA1 and shRNA2) Lipofectamine, the empty vector (NC group) or Lipofectamine2000 (blank control group), and the changes in the expression of Panx-2 was detected with Western blotting. The effects of transfection with a Panx-2 inhibitor on surviving fraction of the cells treated with cisplatin (16 μmol/L) for 24 h, 48 h and 72 h was assessed with MTT assay, and the clonogenic capacity of the cells was evaluated with colony-forming assay. At 8 h after incubation with 16 μmol/L cisplatin, AnnexinV/PI double staining was used to detect the early apoptosis of the cells. After 24 h of treatment with 16 μmol/L cisplatin, the cells were examined for expressions of caspase-3, Bcl-2 and Bax using Western blotting.@*RESULTS@#The expression of Panx-2 was significantly increased in cisplatin-resistant I-10/DDP ( < 0.001) cells and Tcam-2/DDP ( < 0.01) cells as compared with I-10 cells and Tcam-2 cells. Transfection of I-10 cells with shRNA1 and shRNA2 resulted in significantly decreased Panx-2 expression ( < 0.05) and significantly reduced cell surviving fraction ( < 0.001). In the presence of cisplatin, the cells in NC group showed a higher clonogenic efficiency than those in shRNA1 and shRNA2 groups ( < 0.001). The early-stage apoptosis rate of the cells in shRNA1 and shRNA2 groups were significantly higher than that in NC group ( < 0.01). Panx-2 knockdown in I-10 cells significantly increased caspase-3 and Bax expressions ( < 0.05) and significantly decreased the expression of Bcl-2 ( < 0.01).@*CONCLUSIONS@#Down-regulation of Panx-2 channel enhances cisplatin-induced apoptosis in cultured testicular cancer cells.

Quantum Phase Transition of Correlated Iron-Based Superconductivity in LiFe_{1-x}Co_{x}As.

The interplay between unconventional Cooper pairing and quantum states associated with atomic scale defects is a frontier of research with many open questions. So far, only a few of the high-temperature superconductors allow this intricate physics to be studied in a widely tunable way. We use scanning tunneling microscopy to image the electronic impact of Co atoms on the ground state of the LiFe_{1-x}Co_{x}As system. We observe that impurities progressively suppress the global superconducting gap and introduce low energy states near the gap edge, with the superconductivity remaining in the strong-coupling limit. Unexpectedly, the fully opened gap evolves into a nodal state before the Cooper pair coherence is fully destroyed. Our systematic theoretical analysis shows that these new observations can be quantitatively understood by the nonmagnetic Born-limit scattering effect in an s±-wave superconductor, unveiling the driving force of the superconductor to metal quantum phase transition.

Four new sesquiterpene derivatives from Dendrobium findlayanum / 中国天然药物

Three new sesquiterpene glycosides with alloaromadendrane and ylangene-derived type aglycones, named dendrofindlayanosides A-C (1-3), one new cyclopacamphane type sesquiterpene named dendrofindlayanobilin A (4), together with five known compounds have been isolated from stems of Dendrobium findlayanum. Their structures were determined on the basis of spectroscopic and chemical methods.

Investigation on the utilization of parenteral nutrition preparations in 12 Hospitals of Jiangsu / 中华临床营养杂志

Objective To investigate the use of parenteral nutrition preparations in Jiangsu Province,and to provide reference for the standardized management of parenteral nutrition preparations.Methods 720 cases using parenteral nutrition preparations from January 2017 to June 2017 in the department of general surgery of 12 hospitals in Jiangsu province were selected.The rate of nutritional risk screening,the indications of parenteral nutrition,the way of infusion,the rationality and economy of the prescriptions were retrospectively evaluated.The calorie,amino acid content,non-protein calorie/nitrogen ratio,glycolipid ratio and cation concentration of the patients received total parenteral nutrition were calculated.Results The total costs of parenteral nutrition preparations of 720 cases were 1.614 1 millions,and 346 cases did not have the indications for parenteral nutrition.The results of prescription comment showed that only 16 patients were screened for nutritional risk by Nutritional Risk Screening 2002 tool at admission.544 cases were intravenous dripped with amino acid and fat emulsion from peripheral vein.In the 176 total parenteral nutrition prescriptions,there were 39 non-protein calorie/nitrogen ratio cases,15 glycolipid ratio cases,69 cation concentration cases,61 calorie cases and 32 amino acid content cases failing to comply with the recommendation of the guidelines.Only 31 total parenteral nutrition prescriptions were completely reasonable.Conclusion The costs of parenteral nutrition preparations used in hospitals of Jiangsu are high but the rate of rationality is low.Nutrition support team should be established to regulate the use of parenteral nutrition preparations and save medical resources.

Decoupling Carrier Concentration and Electron-Phonon Coupling in Oxide Heterostructures Observed with Resonant Inelastic X-Ray Scattering.

We report the observation of multiple phonon satellite features in ultrathin superlattices of the form nSrIrO_{3}/mSrTiO_{3} using resonant inelastic x-ray scattering (RIXS). As the values of n and m vary, the energy loss spectra show a systematic evolution in the relative intensity of the phonon satellites. Using a closed-form solution for the RIXS cross section, we extract the variation in the electron-phonon coupling strength as a function of n and m. Combined with the negligible carrier doping into the SrTiO_{3} layers, these results indicate that the tuning of the electron-phonon coupling can be effectively decoupled from doping. This work both showcases a feasible method to extract the electron-phonon coupling in superlattices and unveils a potential route for tuning this coupling, which is often associated with superconductivity in SrTiO_{3}-based systems.

Pairing Mechanism in Hund's Metal Superconductors and the Universality of the Superconducting Gap to Critical Temperature Ratio.

We analyze a simple model containing the physical ingredients of a Hund's metal, the local spin fluctuations with power-law correlators, (Ω_{0}/|Ω|)^{γ}, with γ greater than one, interacting with electronic quasiparticles. While the critical temperature and the gap change significantly with varying parameters, the 2Δ_{max}/k_{B}T_{c} remains close to twice the BCS value in agreement with experimental observations in the iron-based superconductors (FeSC).

Imaging antiferromagnetic antiphase domain boundaries using magnetic Bragg diffraction phase contrast.

Manipulating magnetic domains is essential for many technological applications. Recent breakthroughs in Antiferromagnetic Spintronics brought up novel concepts for electronic device development. Imaging antiferromagnetic domains is of key importance to this field. Unfortunately, some of the basic domain types, such as antiphase domains, cannot be imaged by conventional techniques. Herein, we present a new domain projection imaging technique based on the localization of domain boundaries by resonant magnetic diffraction of coherent X rays. Contrast arises from reduction of the scattered intensity at the domain boundaries due to destructive interference effects. We demonstrate this approach by imaging antiphase domains in a collinear antiferromagnet Fe2Mo3O8, and observe evidence of domain wall interaction with a structural defect. This technique does not involve any numerical algorithms. It is fast, sensitive, produces large-scale images in a single-exposure measurement, and is applicable to a variety of magnetic domain types.

Inhibitory effect of different Dendrobium species on LPS-induced inflammation in macrophages via suppression of MAPK pathways / 中国天然药物

Dendrobii Caulis (DC), named 'Shihu' in Chinese, is a precious herb in traditional Chinese medicine. It is widely used to nourish stomach, enhance body fluid production, tonify "Yin" and reduce heat. More than thirty Dendrobium species are used as folk medicine. Some compounds from DC exhibit inhibitory effects on macrophage inflammation. In the present study, we compared the anti-inflammatory effects among eight Dendrobium species. The results provided evidences to support Dendrobium as folk medicine, which exerted its medicinal function partially by its inhibitory effects on inflammation. To investigate the anti-inflammatory effect of Dendrobium species, mouse macrophage cell line RAW264.7 was activated by lipopolysaccharide. The nitric oxide (NO) level was measured using Griess reagent while the pro-inflammatory cytokines were tested by ELISA. The protein expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) phosphorylation were evaluated by Western blotting analysis. Among the eight Dendrobium species, both water extracts of D. thyrsiflorum B.S.Williams (DTW) and D. chrysotoxum Lindl (DCHW) showed most significant inhibitory effects on NO production in a concentration-dependent manner. DTW also significantly reduced TNF-α, MCP-1, and IL-6 production. Further investigations showed that DTW suppressed iNOS and COX-2 expression as well as ERK and JNK phosphorylation, suggesting that the inhibitory effects of DTW on LPS-induced macrophage inflammation was through the suppression of MAPK pathways. In conclusion, D. thyrsiflorum B.S.Williams was demonstrated to have potential to be used as alternative or adjuvant therapy for inflammation.

Inhibitory effect of different Dendrobium species on LPS-induced inflammation in macrophages via suppression of MAPK pathways / 中国天然药物

Dendrobii Caulis (DC), named 'Shihu' in Chinese, is a precious herb in traditional Chinese medicine. It is widely used to nourish stomach, enhance body fluid production, tonify "Yin" and reduce heat. More than thirty Dendrobium species are used as folk medicine. Some compounds from DC exhibit inhibitory effects on macrophage inflammation. In the present study, we compared the anti-inflammatory effects among eight Dendrobium species. The results provided evidences to support Dendrobium as folk medicine, which exerted its medicinal function partially by its inhibitory effects on inflammation. To investigate the anti-inflammatory effect of Dendrobium species, mouse macrophage cell line RAW264.7 was activated by lipopolysaccharide. The nitric oxide (NO) level was measured using Griess reagent while the pro-inflammatory cytokines were tested by ELISA. The protein expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) phosphorylation were evaluated by Western blotting analysis. Among the eight Dendrobium species, both water extracts of D. thyrsiflorum B.S.Williams (DTW) and D. chrysotoxum Lindl (DCHW) showed most significant inhibitory effects on NO production in a concentration-dependent manner. DTW also significantly reduced TNF-α, MCP-1, and IL-6 production. Further investigations showed that DTW suppressed iNOS and COX-2 expression as well as ERK and JNK phosphorylation, suggesting that the inhibitory effects of DTW on LPS-induced macrophage inflammation was through the suppression of MAPK pathways. In conclusion, D. thyrsiflorum B.S.Williams was demonstrated to have potential to be used as alternative or adjuvant therapy for inflammation.

Experimental and Theoretical Modal Analysis of Full-Sized Wood Composite Panels Supported on Four Nodes.

Key elastic properties of full-sized wood composite panels (WCPs) must be accurately determined not only for safety, but also serviceability demands. In this study, the modal parameters of full-sized WCPs supported on four nodes were analyzed for determining the modulus of elasticity (E) in both major and minor axes, as well as the in-plane shear modulus of panels by using a vibration testing method. The experimental modal analysis was conducted on three full-sized medium-density fiberboard (MDF) and three full-sized particleboard (PB) panels of three different thicknesses (12, 15, and 18 mm). The natural frequencies and mode shapes of the first nine modes of vibration were determined. Results from experimental modal testing were compared with the results of a theoretical modal analysis. A sensitivity analysis was performed to identify the sensitive modes for calculating E (major axis: Ex and minor axis: Ey) and the in-plane shear modulus (Gxy) of the panels. Mode shapes of the MDF and PB panels obtained from modal testing are in a good agreement with those from theoretical modal analyses. A strong linear relationship exists between the measured natural frequencies and the calculated frequencies. The frequencies of modes (2, 0), (0, 2), and (2, 1) under the four-node support condition were determined as the characteristic frequencies for calculation of Ex, Ey, and Gxy of full-sized WCPs. The results of this study indicate that the four-node support can be used in free vibration test to determine the elastic properties of full-sized WCPs.