Biomedical subjects

Chao Zheng

Publications and source records attributed to Chao Zheng.

12 recordsLinked to original sources

PubMed2026

Spectral-Proteomic Integration Analysis (SPIA) Deciphers Molecular Trajectories of Breast Cancer and Enables Multitarget Therapeutic Assessment.

Raman spectroscopy and mass spectrometry-based proteomics offer deeply complementary yet largely disconnected views of cancer biology: the former provides a label-free, real-time biochemical phenotype, while the latter delivers a quantitative inventory of specific protein effectors. Bridging this gap remains a fundamental challenge in analytical biomedicine. Here, we introduce Spectral-Proteomic Integration Analysis (SPIA)─a novel, data-driven integrative framework that systematically links Raman spectroscopic phenotypes with quantitative proteomic profiles through machine learning and statistical correlation. Using a DMBA-induced rat breast cancer model with and without Toremifene (TOR) intervention, SPIA dynamically maps tumor microenvironment remodeling, capturing progressive collagen deposition and lipid metabolic reprogramming. An SVM classifier trained on Raman spectra achieves exceptional diagnostic accuracy (AUC ≥ 99.0%) and successfully predicts TOR therapeutic response. Proteomic analysis identifies 1,350 differentially expressed proteins, with convergent machine learning feature selection (LASSO, Random Forest, XGBoost) pinpointing core regulators including Luc7l2, Nucb1, Cbx3, and Csnk2a1. Crucially, Spearman correlation analysis between key Raman bands and core DEPs reveals strong, statistically robust associations (median ρ ∼ 0.75 in the 1533-1669 cm-1 region), empirically validating SPIA's core integrative logic. Leveraging this multimodal map, we elucidate a multitarget mechanism for TOR involving concurrent suppression of collagen deposition and correction of aberrant lipid metabolism. SPIA establishes a powerful, generalizable paradigm for integrating phenotypic and molecular data, with broad implications for biomarker discovery, drug mechanism elucidation, and precision oncology.

Animals↗

PubMed2007

Molecularly imprinted polymers as a tool for separation in CEC.

Molecularly imprinted polymers (MIPs) are synthesized in the presence of a template which results in the formation of specific recognition cavities complementary to the template in shape and chemical functionality. One of the most successful application areas of MIPs is chromatographic sorbents, which are tailor-made synthetic polymers for a given analyte. However, low efficiency of MIP columns is often observed because of slow kinetics of the template. CEC-based MIPs are thought to improve efficiency of MIP-based separation due to the enhanced flow dynamics of CEC. Another attractive feature is the miniaturized format of CEC, so that fewer templates or monomers for the molecular imprinting are consumed, a characteristic desired for 'green chemistry'. The small dimensions of a capillary demand the development of novel polymer formats that can be applied to a miniaturized system. This review discusses the various formats, i.e., the micro- or nanoparticle, the coating and the monolith, for application in CEC as well as the use in MIP syntheses and characteristics.

Capillary Electrochromatography↗

PubMed2006

Conformational studies of cyclopropylmethyl isothiocyanate from temperature-dependent FT-IR spectra of rare gas solutions and ab initio calculations.

Variable temperature (-55 to -150 degrees C) studies of the infrared spectra (3200-100 cm(-1)) of cyclopropylmethyl isothiocyanate, c-C(3)H(5)CH(2)NCS, dissolved in liquefied rare gases (Xe and Kr), have been carried out. The infrared spectra of the gas and solid, as well as the Raman spectrum of the liquid, have also been recorded from 3200 to 100 cm(-1). By analyzing six conformer pairs in xenon solutions, a standard enthalpy difference of 228 +/- 23 cm(-1) (2.73 +/- 0.27 kJ.mol(-1)) was obtained with the gauche-cis (the first designation indicates the orientation of the CNCS group with respect to the three-membered ring, the second designation indicates the relative orientation of the NCS group with respect to the bridging C-C bond) rotamer the more stable form, and it is also the only form present in polycrystalline solid. Given statistical weights of 2:1 for the gauche-cis and cis-trans forms (the only stable conformers predicted); the abundance of cis-trans conformer present at ambient temperature is 14 +/- 2%. The potential surface describing the conformational interchange has been analyzed, and the corresponding two-dimensional Fourier coefficients were obtained. From MP2 ab initio calculations utilizing various basis sets with diffuse functions, the gauche-cis conformer is predicted to be more stable by 159-302 cm(-1), which is consistent with the experimental results. However, without diffuse functions, the conformational energy differences are nearly zero even with large basis sets. For calculations with density functional theory by the B3LYP method, basis sets without diffuse functions also predict smaller energy differences between the conformers, although not nearly as small as the MP2 results. A complete vibrational assignment for the gauche-cis conformer is proposed, and several fundamentals for the cis-trans conformer have been identified. The structural parameters, dipole moments, conformational stability, vibrational frequencies, and infrared and Raman intensities have been predicted from ab initio calculations and compared to the experimental values when applicable; the r(0) structural parameters are also estimated. The energies for the linear CNCS moiety were calculated. These experimental and theoretical results are compared to the corresponding quantities of some similar molecules.

Journal Article↗

PubMed2006

Microwave spectra, ab initio calculations, and r0 structural parameters for (methylamino)thiophosphoryl difluoride.

The microwave spectra of (methylamino)thiophosphoryl difluoride, CH(3)NHP(=S)F(2), and two deuterated species, CH(3)NDP(=S)F(2) and CD(3)NHP(=S)F(2), have been investigated in the region from 26.5 to 39.0 GHz. The rotational constants of the ground vibrational state have been determined and have been shown to be only consistent with the trans conformer (CH(3) group antiperiplanar to the P=S bond) with C(s) symmetry. The a-type R branch transitions have been assigned for the trans conformer for the three isotopomers on the basis of the rigid rotor model. Near-trans and near-cis forms without molecular planes of symmetry are predicted by all ab initio calculations with the near-trans form being more stable. However, the double-well potentials governing the interchange between the two enantiomeric near-trans as well as the two near-cis forms are too shallow to accommodate the zero-point energies of the nu(24) asymmetric torsion. Thus, the trans conformation with C(s) symmetry may be more accurate in explaining the microwave experimental data. The "adjusted" r(0) structural parameters have been obtained by systematically adjusting the ab initio MP2(full)/6-311+G(d,p) structure of the trans conformer with C(s) symmetry to fit the microwave rotational constants. The determined heavy atom distances are r(C-N) = 1.459(5), r(P-N) = 1.621(5), r(P=S) = 1.879(5), and r(P-F) = 1.550(5) A, and the heavy atom angles are angleCNP = 124.7(5) degrees , angleNPS = 118.3(5) degrees , angleNPF = 103.2(5) degrees , angleFPS = 117.0(5) degrees , and angleFPF = 94.6(5) degrees . The adjusted r(0) parameters have also been obtained for aminodifluorophosphine, H(2)NPF(2), with a slightly pyramidal -PNH(2) moiety. The results indicate that the previously reported short distance of 0.981(5) A for the N-H(o)(outer) bond from the microwave study is too short, and the adjusted r(0) value of 1.007(3) A is obtained from the combined data. Adjusted r(0) parameters are also reported for (dimethylamino)difluorophosphine, (CH(3))(2)NPF(2), with C(s) symmetry with the PNC(2) portion of the molecule being planar. The previously reported C-H distances from the electron diffraction study are too long, and the anglePNC(i) and angleC(o)NC(i) angles are also found to be in error. These results provide a reasonable explanation why the microwave and electron diffraction results differ for the structures of these latter two molecules.

Journal Article↗

PubMed2006

Conformational stability from temperature-dependent fourier transform infrared spectra of noble gas solutions, r0 structural parameters, and barriers to internal rotation for ethylamine.

Variable temperature (-55 to -145 degrees C) studies of the infrared spectra (3500 to 100 cm(-1)) of ethylamine, CH(3)CH(2)NH(2), dissolved in liquid krypton and/or xenon have been recorded. From these data, the enthalpy differences have been determined to be 54 +/- 4 cm(-1) (0.65 +/- 0.05 kJ/mol), with the trans conformer (methyl group relative to the lone pair of electrons on nitrogen) being the more stable form. It is estimated that there is 61 +/- 1% of the doubly degenerate gauche form present at ambient temperature. The conformational energetics have been calculated with the Møller-Plesset perturbation method to the second order (MP2(full)) and the fourth order (MP4(SDTQ)) as well as with density functional theory by the B3LYP method utilizing a variety of basis sets. Basis sets with diffuse functions lead to incorrect prediction of the conformational stability. On the basis of the frequencies of the torsional transitions along with the determined experimental enthalpy difference and gauche dihedral angle, the potential function governing conformational interchange has been obtained, and the determined Fourier cosine coefficients are V(1) = -207 +/- 48, V(2) = 320 +/- 67, V(3) = 1072 +/- 25, V(4) = 55 +/- 11, and V(5) = -96 +/- 28 cm(-1), with a trans-to-gauche barrier of 1286 cm(-1), and a gauche-to-gauche barrier of 715 cm(-1). The 3-fold methyl rotational barriers have been determined to be 1241 +/- 4 and 1281 +/- 10 cm(-1) for the gauche and trans conformers, respectively. By utilizing the previously reported microwave rotational constants combined with the structural parameters predicted at the MP2(full)/6-311+ G(d,p) level, adjusted r(0) structural parameters have been obtained. A complete vibrational assignment is given for the trans conformer, which is supported by normal coordinate calculations utilizing scaled force constants from ab initio B3LYP/6-311++G(3df,3pd) calculations. Proposed assignments are also made for the fundamentals of the gauche conformer. The results of these spectroscopic and theoretical studies are discussed and compared to the corresponding results for similar molecules.

Ethylamines↗

PubMed2006

A general strategy for the facile synthesis of 2,7-dibromo-9-heterofluorenes.

[reaction: see text] A facile, highly efficient, and economical procedure for the preparation of 6,6'-diiodo-4,4'-dibromo-3,3'-dimethoxylbiphenyl has been found. From this compound, a general synthetic strategy for the preparation of 2,7-dibromo-9-heterofluorenes has been developed. Five 2,7-dibromo-9-heterofluorenes have been easily synthesized for the first time according to the procedure presented, opening the door to new classes of inorganic and organometallic conjugated polymeric materials of polyheterofluorenes.

Journal Article↗

PubMed2006

[Separation and recognition of biomacromolecule by molecular imprinting technique].

Molecular imprinting technique is a novel technique based on mimicking specific action of antibody-antigen. The emergence and the development of the technique are reviewed in this article. The focuses of this article include the introductions of the synthesis conditions, the comparisons of the various approaches on preparation methods as well as the recognition mechanisms of the biomacromolecule imprinted polymers. The primary synthetic methods include the embed technique, the surface imprinting procedure and the epitope approach. The epitope approach is based on using a short peptide as a template that represents only part of a larger peptide or protein, which in turn can be recognized by the synthesized polymer. This approach for the development of the biomacromolecule imprinted polymers selective to proteins is attractive from an economic viewpoint: a small peptide is usually less expensive, and the quantity necessary for the polymer preparation is more readily available than that of the corresponding protein. In the end, the limitations and the prospective applications of this biomacromolecular imprinted technique are also discussed.

Epitope Mapping↗

PubMed2005

Conformational stabilities of 1,1-dicyclopropylethene determined from variable-temperature infrared spectra of xenon solutions and ab initio calculations.

The infrared (3200-40 cm(-1)) spectra of gaseous and solid 1,1-dicyclopropylethene, (c-C3H5)2C=CH2, along with the Raman (3200-40 cm(-1)) spectra of liquid and solid phases, have been recorded. The major trans-gauche (C=C bond trans to one ring with the other ring rotated about 60 degrees from the C=C bond, trivial C(1) symmetry) and gauche-gauche (the two three-membered rings rotated oppositely about 60 degrees from the C=C bond, C2 symmetry) rotamers have been confidently identified in the fluid phases, but no definitive spectroscopic evidence was found for the gauche-gauche' form (the two three-membered rings rotated to the same side about 60 degrees from the C=C bond, Cs symmetry), which is calculated to be present in no more than 6% at ambient temperature. Variable-temperature (-55 to -100 degrees C) studies of the infrared spectra of the sample dissolved in liquid xenon have been carried out. Utilizing six different combinations of pairs of bands from the C1 and C2 conformers, the average enthalpy difference between these two has been determined to be 146 +/- 30 cm(-1) (1.75 +/- 0.36 kJ x mol(-1)), with the C1 form more stable. Given statistical weights of 2:1:1 respectively for the C1, C2, and Cs forms, it is estimated that there are 75 +/- 2% C(1) and 19 +/- 1% C2 conformers present at ambient temperature. By utilizing predicted frequencies, infrared intensities, Raman activities, and band envelopes from scaled MP2(full)/6-31G(d) ab initio calculations, a complete vibrational assignment is made for the C1 form and a number of fundamentals of the C2 conformer have been identified. The structural parameters, dipole moments, and conformational stabilities have been obtained from ab initio calculations at the level of Hartree-Fock (RHF), the perturbation method to second order with full electron correlation (MP2(full)), and hybrid density functional theory (DFT) by the B3LYP method with a variety of basis sets. The predicted conformational stabilities from the MP2 calculations with relatively large basis sets are consistent with the experimental results. Structural parameters are estimated from the MP2(full)/6-311+G(d,p) predictions which are compared to the previously reported electron diffraction parameters. These experimental and theoretical results are compared to the corresponding quantities of some similar molecules.

Journal Article↗

PubMed2005

Is 2-cyclopropylpropene really gauche?

Infrared spectra of gaseous and solid 2-cyclopropylpropene (2-CPP, c-C3H5C (CH3)CH2) have been recorded from 3500 to 40 cm-1, and Raman spectra (3200-150 cm-1) of the liquid as well as mid-infrared spectra of 2-CPP in liquid krypton solution (from -105 to -150 degrees C) were also obtained. Ab initio calculations, with basis sets up to 6-311+G(2df, 2pd), were carried out for this molecule, using the restricted Hartree-Fock (RHF) approach, with full electron correlation by the perturbation method to second order (MP2(full)) and density functional theory (DFT) by the B3LYP method. The combination of the experimental and computational results (particularly with the higher basis sets) unequivocally identifies the more stable conformer of 2-CPP as the trans form, with the gauche rotamer higher in energy, but also stable. The cis structure of this compound is not observed experimentally, and is predicted by the computational approaches to be a transition state. By studying the temperature variation of two well-resolved sets of conformational doublets of 2-CPP dissolved in liquid krypton, an average enthalpy difference between conformers of 182+/-18 cm-1 (2.18+/-0.22 kJ mol-1) has been determined, with the trans conformation lower in energy in the fluid states, and the sole conformer present in the polycrystalline solid phase. This enthalpy difference corresponds to an ambient temperature conformational equilibrium in the fluid phases of 2-cyclopropylpropene containing approximately 55+/-2% of the more stable trans rotameric form. A complete vibrational assignment for the trans conformer of 2-CPP is given, and many of the bands of the gauche rotamer have also been assigned. Structural parameters, dipole moments, and rotational constants for this molecule have been calculated at the MP2(full)/6-311+G(d,p) level, and these results--as well as the results from the experimental studies--are compared to similar quantities in related compounds.

Alkenes↗

PubMed2005

[Separation of interleukin-18 on a weak anion exchange monolithic column].

A weak anion exchange column was prepared and a separation method of interleukin-18 (IL-18) was developed on the column. The chromatographic column with glycidyl methacrylate as functional monomer and ethylene dimethacrylate as cross-linker was prepared by a free radical polymerization within a 64 mm x 4.6 mm i.d. column. The epoxide groups of the column were modified by a reaction with diethylamine that affords ionizable functionalities required for ion exchange chromatography. The influences of the contents of the cross-linker and porogen on column pressure were investigated. The factors influencing the separation, such as stationary phases, buffers, pH values, salts, and contents of organic solvent, were studied. The optimal conditions for separating IL-18 from its related proteins were obtained. The proposed method is simple, sensitive, rapid and reproducible.

Anion Exchange Resins↗

PubMed2004

Conformational stability from variable temperature infrared spectra of krypton solutions, ab initio calculations, vibrational assignment, and r0 structural parameters of 1,3-difluoropropane.

The infrared spectra (3200-400 cm(-1)) of krypton solutions of 1,3-difluoropropane, FCH2CH2CH2F, at variable temperatures (-105 to -150 degrees C) have been recorded. Additionally, the infrared spectra (3200-50 cm(-1)) of the gas and solid have been recorded as well as the Raman spectrum of the liquid. From a comparison of the spectra of the fluid phases with that in the solid, all of the fundamental vibrations of the C2 conformer (gauche-gauche) where the first gauche indicates the form for one of the CH2F groups and the second gauche the other CH2F, and many of those for the C1 form (trans-gauche) have been identified. Tentative assignments have been made for a few of the fundamentals of the other two conformers, i.e. C2v (trans-trans) and Cs (gauche-gauche'). By utilizing six pairs of fundamentals for these two conformers in the krypton solutions, an enthalpy difference of 277 +/- 28 cm(-1) (3.31 +/- 0.33 kJ mol(-1)) has been obtained for the C2 versus C1 conformer with the C2 conformer the more stable form. For the C2v conformer, the enthalpy difference has been determined to be 716 +/- 72 cm(-1) (8.57 +/- 0.86 kJ mol(-1)) and for the Cs form 971 +/- 115 cm(-1) (11.6 +/- 1.4 kJ mol(-1)). It is estimated that there is 64 +/- 3% of the C2 form, 34 +/-3% of the C1 form, 1% of the C2v form and 0.6% of the Cs conformer present at ambient temperature. Equilibrium geometries and total energies of the four stable conformers have been determined from ab initio calculations with full electron correlation by the perturbation method to second order as well as by hybrid density functional theory calculations with the B3LYP method using a number of basis sets. The MP2 calculations predict the C1 conformer stability to be slightly higher than the experimentally determined value whereas for the C2v and Cs conformers the predicted energy difference is much larger than the experimental value. The B3LYP calculations predict a better energy difference for both the C1 and C2v as well as for the Cs conformers than the MP2 values. A complete vibrational assignment is proposed for the C2 conformer and many of the fundamentals have been identified for the C1 form based on the force constants, relative intensities and rotational-vibrational band contours obtained from the predicted equilibrium geometry parameters. By combining previously reported rotational constants for the C2 and C1 conformers with ab initio MP2/6-311 + G(d, p) predicted parameters, adjusted r0 parameters have been obtained for both conformers. Comparisons are made with the parameters obtained for some other molecules containing the FCH2 group. The spectroscopic and theoretical results are compared to the corresponding properties for some similar molecules.

Drug Stability↗

PubMed2003

Spectra and structure of silicon-containing compounds. Part XXXVIII: Infrared and Raman spectra, vibrational assignment, conformational stability, and ab initio calculations of vinyldifluorosilane.

Infrared spectra (3500-50 cm(-1)) of gaseous and solid, and Raman spectrum (3500-30 cm(-1)) of liquid vinyldifluorosilane, CH(2)z.dbnd6;CHSiF(2)H, are reported. Both the cis and gauche rotamers have been identified in the fluid phases. From temperature-dependent FT-infrared spectra of krypton solutions, it is shown that the cis conformer is more stable than the gauche form by 119+/-12 cm(-1) (1.42+/-0.14 kJ mol(-1)). At ambient temperature there is 53+/-2% of the gauche conformer present. Complete vibrational assignments are provided for the cis conformer and several modes are identified for the gauche form. Harmonic force constants, fundamental frequencies, infrared intensities, and Raman activities have been obtained from MP2/6-31G(d) calculations with full electron correlation. The optimized geometries and conformational stabilities have also been obtained from ab initio MP2/6-31G(d), MP2/6-311+G(d,p), and MP2/6-311+G(2d,2p) calculations with full electron correlation as well as from density functional theory calculations (DFT) by the B3LYP method. The SiH bond distances (r(0)) of 1.472 and 1.471 A have been obtained for the cis and gauche conformers, respectively, from the silicon-hydrogen stretching frequencies. These results are compared to the corresponding quantities of the corresponding carbon analogue as well as with some similar molecules.

Molecular Conformation↗