18 research outputs found
An empirical and analytical study of chinese mergers and acquisitions
Over the last several years (and especially since China's admission to the World Trade Organisation in 2001) merger and acquisition (M&A) activities in China have increased significantly as a result of the rapid growth in the Chinese economy and the measures which the Chinese government has taken to modernise the laws and regulations which govern its securities markets. Despite this, only a few researchers have studied M&A activities in China in any depth. Moreover, such research as has been conducted on Chinese M&A activities is mainly concerned with the laws and regulations affecting the area and not with their economic consequences. Hence, the particular concern of this dissertation is with the economic benefits that accrue to the shareholders of Chinese acquiring and target firms from the M&A activities that have occurred in the People s Republic of China over the last twenty years. In particular, our study encompasses a theoretical, institutional and empirical analysis of Chinese M&A activities.
M&A activities in China are governed by a number of laws and regulations of which the Takeover Measures, 2006, is undoubtedly the most important. Our analysis in the early part of the dissertation summarises the legal framework under which M&A activities are conducted in China. In particular, the Takeover Measures, 2006 aim to make Chinese laws in the M&A area more compatible with best international practice. Furthermore, a new Anti-Monopoly Law, which addresses the anti-trust issues associated with mergers and acquisitions came into force on 1 August 2008. Amongst other things, this new Anti-Monopoly Law addresses issues of anti-trust and declaration thresholds in M&A activities in China. Besides these issues, the early chapters of the dissertation summarise the Chinese laws dealing with cross-border mergers and acquisitions, the laws relating to the issue of new shares, the laws relating to share swap transactions and the important provisions affecting the regulation of special purpose companies (SPCs).
The dissertation then turns to an empirical analysis of the economic benefits which accrue to the shareholders of Chinese target and Chinese acquiring firms as a result of their M&A activities. Our analysis is based on the standard market model methodology using both the Dimson (1979) and Ordinary Least Squares (OLS) estimates of equity betas. We also employ an hitherto unused nonparametric testing procedure based on the Corrado (1989) rank test in order to enhance the robustness of our empirical analysis. Suffice it to say that the empirical analysis summarised in the dissertation shows that there are significant abnormal returns around the takeover announcement date for the holders of equity securities in Chinese target firms. This is a result which mirrors much of the empirical research conducted on M&A activities in western economies. Interestingly, however, a significant proportion of these abnormal returns decay away within a few weeks following the takeover announcement date. In contrast, there are few, if any, economic benefits for the holders of equity securities in Chinese acquiring firms from their M&A activities. In this respect our results for Chinese acquiring firms are very similar to those obtained by researchers for western acquiring firms, although there are some important differences. In particular, there appear to be statistically significant and positive abnormal returns for shareholders of Chinese acquiring firms around the takeover announcement date but these generally decay away over the next ten to fifteen trading days thereby leaving the shareholders of Chinese acquiring firms with no significant benefits from their M&A activities. We provide some possible explanations for this phenomenon by linking our empirical results with the Chinese political, economic and capital systems.
A fundamental decision the directors of acquiring firms must make is whether the mode of consideration for takeovers ought to be in cash or some alternative medium of exchange. Prior research in western countries shows that the mode of consideration used in takeovers can have a significant impact on the abnormal returns which accrue to the shareholders of both acquiring and target firms. Our empirical analysis of this issue shows that when the mode of consideration is purely in cash the abnormal returns which accrue to the shareholders of Chinese target firms around the takeover announcement date are positive and significantly different from zero. In contrast, there are no economic benefits (and indeed, probably economic losses) for the shareholders of Chinese target firms when the consideration for takeovers is other than purely in cash. For Chinese acquiring firms there are significant positive abnormal returns when the consideration for takeovers is other than purely in cash. However, when cash is used as the sole mode of consideration by Chinese acquiring firms there are very few, if any, economic benefits for their shareholders.
The concluding sections of the dissertation note that our calculation of the abnormal returns that accrue to firms involved in Chinese M&A activities is based exclusively on the standard market model - which is empirical counterpart of the Capital Asset Pricing Model (CAPM). In recent years, however, Fama and French (1992, 1993, 1995, 1996) amongst other authors have suggested that the CAPM has serious deficiencies and that these deficiencies flow through to the standard market model on which the empirical analysis of Chinese M&A activities summarised in this dissertation is based. We show, however, that the Fama and French Asset Pricing Model (1992, 1993, 1995, 1996) has numerous deficiencies of its own and that to base the calculation of abnormal returns upon this model has the potential to lead to a seriously flawed analysis of the abnormal returns which accrue to the shareholders of Chinese firms involved in M&A activities and on which our empirical analysis is based.
Key Words: M&A activities, Modified Corrado test, Corrado test, Patell test, average abnormal returns (AARs), cumulative average abnormal returns (CAARs), mode of consideration, A shareholders, B shareholders, H shareholders, Chinese target firms, Chinese acquiring firms
Week 120 Efficacy of Tenofovir, Lamivudine and Lopinavir/r-Based Second-Line Antiretroviral Therapy in Treatment-Experienced HIV Patients
<div><p>Background</p><p>Tenofovir (TDF) and ritonavir-boosted lopinavir (LPV/r) were not introduced to China as second-line medications until 2009. The efficacy and safety of TDF/3TC/LPV/r based second-line regimen have not been evaluated in Chinese HIV patients who failed first-line regimens.</p><p>Methods</p><p>This was a multicenter cohort study recruiting patients from Beijing, Shanghai, Guangdong, and Henan provinces between November 2008 and January 2010. Eighty HIV infected patients failing first-line regimens with serum creatinine lower than 1.5 times the upper limit of normal received TDF+ lamivudine (3TC)+ LPV/r were followed up for 120 weeks. CD4 cell count, viral load, and estimated glomerular filtration rate (eGFR) were monitored at each visit.</p><p>Results</p><p>At baseline, 31.2% and 48.8% of patients had moderate/high-level resistance to TDF and 3TC, respectively; while 2.5% of patients had only low-level resistance to LPV/r. During 120 weeks of follow-up, virological suppression rate reached over 70% (<40 copies/ml) and 90% (<400 copies/ml), and median CD4 cell count increased from 157 cells/μL at baseline to 307 cells/μL at week 120. Baseline drug-resistance mutations had no impact on the efficacy of second-line antiretroviral therapy. Median eGFR dropped from 104.7 ml/min/1.73m<sup>2</sup> at baseline to 95.6 ml/min/1.73m<sup>2</sup> at week 24 and then recovered after week 96.</p><p>Conclusion</p><p>This study for the first time demonstrated that TDF+ 3TC+ LPV/r was efficacious as second-line regimen with acceptable nephrotoxicity profiles in patients who failed zidovudine or stavudine based first-line regimens in China.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT00872417?term=NCT00872417&rank=1" target="_blank">NCT00872417</a></p></div
Transmitted drug resistants (TDRs) at baseline (n = 80).
<p>NRTI, nucleoside reverse transcriptase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor; TDR, transmitted drug resistant.</p><p>*, p<0.05</p><p>Transmitted drug resistants (TDRs) at baseline (n = 80).</p
Baseline characteristics (n = 80).
<p>MSM, men who have sex with men; eGFR, estimated glomerular filtration rate; HBsAg, hepatitis B virus S antigen; HCVAb, hepatitis C virus antibody; DRM, drug resistance mutation; TDF, tenofovir; 3TC, lamivudine; LPV/r, ritonavir-boosted lopinavir.</p><p>Baseline characteristics (n = 80).</p
DataSheet_2_Altered plasma metabolites and inflammatory networks in HIV-1 infected patients with different immunological responses after long-term antiretroviral therapy.xlsx
BackgroundChronic metabolic changes relevant to human immunodeficiency virus type 1 (HIV-1) infection and in response to antiretroviral therapy (ART) remain undetermined. Moreover, links between metabolic dysfunction caused by HIV and immunological inflammation in long-term treated individuals have been poorly studied.MethodsUntargeted metabolomics and inflammatory cytokine levels were assessed in 47 HIV-infected individuals including 22 immunological responders (IRs) and 25 non-responders (INRs) before and after ART. The IRs and INRs were matched by age, gender, baseline viral load, and baseline CD4+T cell counts. Another 25 age-matched uninfected healthy individuals were also included as controls.ResultsAmong the 770 plasma compounds detected in the current study, significant changes were identified in lipids, nucleotides, and biogenic amino acids between HIV-infected patients and healthy controls. Principal Component Analysis (PCA) and the Random Forest (RF) model suggested that levels of selected metabolites could differentiate HIV-infected patients clearly from healthy controls. However, the metabolite profiles identified in our patients were similar, and only three metabolites, maltotetraose, N, N-dimethyl-5-aminovalerate, and decadienedioic acid (C10:2-DC), were different between IRs and INRs following long-term ART. The pathway enrichment analysis results revealed that disturbances in pyrimidine metabolism, sphingolipid metabolism, and purine metabolism after HIV infection and these changes did not recover to normal levels in healthy controls even with suppressive ART. Correlation analysis of the metabolism-immune network indicated that interleukin (IL)-10, D-dimer, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), and TNF-RII were positively correlated with most of the significantly changed lipid and amino acid metabolites but negatively correlated with metabolites in nucleotide metabolism.ConclusionsSignificant changes in many metabolites were observed in HIV-infected individuals before and after ART regardless of their immunological recovery status. The disturbed metabolic profiles of lipids and nucleotides in HIV infection did not recover to normal levels even after long-term ART. These changes are correlated with modified cytokines and biomarkers of chronic non-AIDS events, warranting tryout of interventions other than ART.</p
DataSheet_1_Altered plasma metabolites and inflammatory networks in HIV-1 infected patients with different immunological responses after long-term antiretroviral therapy.docx
BackgroundChronic metabolic changes relevant to human immunodeficiency virus type 1 (HIV-1) infection and in response to antiretroviral therapy (ART) remain undetermined. Moreover, links between metabolic dysfunction caused by HIV and immunological inflammation in long-term treated individuals have been poorly studied.MethodsUntargeted metabolomics and inflammatory cytokine levels were assessed in 47 HIV-infected individuals including 22 immunological responders (IRs) and 25 non-responders (INRs) before and after ART. The IRs and INRs were matched by age, gender, baseline viral load, and baseline CD4+T cell counts. Another 25 age-matched uninfected healthy individuals were also included as controls.ResultsAmong the 770 plasma compounds detected in the current study, significant changes were identified in lipids, nucleotides, and biogenic amino acids between HIV-infected patients and healthy controls. Principal Component Analysis (PCA) and the Random Forest (RF) model suggested that levels of selected metabolites could differentiate HIV-infected patients clearly from healthy controls. However, the metabolite profiles identified in our patients were similar, and only three metabolites, maltotetraose, N, N-dimethyl-5-aminovalerate, and decadienedioic acid (C10:2-DC), were different between IRs and INRs following long-term ART. The pathway enrichment analysis results revealed that disturbances in pyrimidine metabolism, sphingolipid metabolism, and purine metabolism after HIV infection and these changes did not recover to normal levels in healthy controls even with suppressive ART. Correlation analysis of the metabolism-immune network indicated that interleukin (IL)-10, D-dimer, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), and TNF-RII were positively correlated with most of the significantly changed lipid and amino acid metabolites but negatively correlated with metabolites in nucleotide metabolism.ConclusionsSignificant changes in many metabolites were observed in HIV-infected individuals before and after ART regardless of their immunological recovery status. The disturbed metabolic profiles of lipids and nucleotides in HIV infection did not recover to normal levels even after long-term ART. These changes are correlated with modified cytokines and biomarkers of chronic non-AIDS events, warranting tryout of interventions other than ART.</p
Ultrabroad Dynamic All-Solid-State Radiation Dose Detector Based on a 0D Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> Perovskite-Like Single Crystal
Radiation dose detectors based on a gas-filled detecting
mode play
an important role in cancer radiation therapy, nuclear accident early
warning, and radiation protection but still suffer from frequent air
density corrections, a high working voltage, and a long stability
time. Therefore, to tackle these issues, the development of high-performance
all-solid-state radiation dose detectors is urgently needed. Here,
we demonstrated a prototype of a highly sensitive all-solid-state
radiation dose detector based on a highly efficient Cs3Cu2I5 perovskite-like single crystal and a
Si photodetector with a heterojunction structure. The Cs3Cu2I5-based detector exhibits an ultrabroad
dynamic range of 11.45 mGy·h–1 to 107.3 Gy·h–1, covering nearly 5 orders of magnitude for γ-ray
with the upper limit being 100 times higher than that of Cs3Cu2I nanocrystal of 0.846 Gy·h–1 and the detection limit approaching the lower limit of the radiotherapy
level (10 mGy·h–1). Moreover, it has an outstanding
linear response with a linear correlation coefficient (R2) of 0.9999 for the X/γ-ray incident dose rate
and a good repeatable response deviation of less than 0.3% for γ-rays,
which is comparable to classical ionization chamber detectors. This
work opens a horizon of developing ultrabroad dynamic, highly sensitive,
and low-power consumption all-solid-state radiation dose detectors
based on perovskite-like single-crystal scintillators
Additional file 1: Table S1. of A higher CD4/CD8 ratio correlates with an ultralow cell-associated HIV-1 DNA level in chronically infected patients on antiretroviral therapy: a case control study
Factors associated with an ultralow HIV-1 DNA level (<20 copies/106 PBMCs) at week 96. Only patients with undetectable HIV-1 RNA at week 96 were analyzed. (DOCX 20 kb
Image_6_Association Between Gut Microbiota and CD4 Recovery in HIV-1 Infected Patients.TIF
<p>Composition of the gut microbiota has been linked with human immunedeficiency virus (HIV)-infected patients on antiretroviral therapy (ART). Evidence suggests that ART-treated patients with poor CD4<sup>+</sup> T-cell recovery have higher levels of microbial translocation and immune activation. However, the association of the gut microbiota and immune recovery remains unclear. We performed a cross-sectional study on 30 healthy controls (HC) and 61 HIV-infected individuals, including 15 immunological ART responders (IRs), 20 immunological ART non-responders (INRs) and 26 untreated individuals (VU). IR and INR groups were classified by CD4<sup>+</sup> T-cell counts of ≥350 cells/mm<sup>3</sup> and <350 cells/mm<sup>3</sup> after 2 years of ART, respectively. Each subject’s gut microbiota composition was analyzed by metagenomics sequencing. Levels of CD4<sup>+</sup> T cells, CD8<sup>+</sup>HLA-DR<sup>+</sup> T cells and CD8<sup>+</sup>CD38<sup>+</sup> T cells were measured by flow cytometry. We identified more Prevotella and fewer Bacteroides in HIV-infected individuals than in HC. Patients in INR group were enriched with Faecalibacterium prausnitzii, unclassified Subdoligranulum sp. and Coprococcus comes when compared with those in IR group. F. prausnitzii and unclassified Subdoligranulum sp. were overrepresented in individuals in VU group with CD4<sup>+</sup> T-cell counts <350 cells/mm<sup>3</sup>. Moreover, we found that the relative abundance of unclassified Subdoligranulum sp. and C. comes were positively correlated with CD8<sup>+</sup>HLA-DR<sup>+</sup> T-cell count and CD8<sup>+</sup>HLA-DR<sup>+</sup>/CD8<sup>+</sup> percentage. Our study has shown that gut microbiota changes were associated with CD4<sup>+</sup> T-cell counts and immune activation in HIV-infected subjects. Interventions to reverse gut dysbiosis and inhibit immune activation could be a new strategy for improving immune reconstitution of HIV-1-infected individuals.</p
Image_4_Association Between Gut Microbiota and CD4 Recovery in HIV-1 Infected Patients.TIF
<p>Composition of the gut microbiota has been linked with human immunedeficiency virus (HIV)-infected patients on antiretroviral therapy (ART). Evidence suggests that ART-treated patients with poor CD4<sup>+</sup> T-cell recovery have higher levels of microbial translocation and immune activation. However, the association of the gut microbiota and immune recovery remains unclear. We performed a cross-sectional study on 30 healthy controls (HC) and 61 HIV-infected individuals, including 15 immunological ART responders (IRs), 20 immunological ART non-responders (INRs) and 26 untreated individuals (VU). IR and INR groups were classified by CD4<sup>+</sup> T-cell counts of ≥350 cells/mm<sup>3</sup> and <350 cells/mm<sup>3</sup> after 2 years of ART, respectively. Each subject’s gut microbiota composition was analyzed by metagenomics sequencing. Levels of CD4<sup>+</sup> T cells, CD8<sup>+</sup>HLA-DR<sup>+</sup> T cells and CD8<sup>+</sup>CD38<sup>+</sup> T cells were measured by flow cytometry. We identified more Prevotella and fewer Bacteroides in HIV-infected individuals than in HC. Patients in INR group were enriched with Faecalibacterium prausnitzii, unclassified Subdoligranulum sp. and Coprococcus comes when compared with those in IR group. F. prausnitzii and unclassified Subdoligranulum sp. were overrepresented in individuals in VU group with CD4<sup>+</sup> T-cell counts <350 cells/mm<sup>3</sup>. Moreover, we found that the relative abundance of unclassified Subdoligranulum sp. and C. comes were positively correlated with CD8<sup>+</sup>HLA-DR<sup>+</sup> T-cell count and CD8<sup>+</sup>HLA-DR<sup>+</sup>/CD8<sup>+</sup> percentage. Our study has shown that gut microbiota changes were associated with CD4<sup>+</sup> T-cell counts and immune activation in HIV-infected subjects. Interventions to reverse gut dysbiosis and inhibit immune activation could be a new strategy for improving immune reconstitution of HIV-1-infected individuals.</p