Jun Pan

Anhui University · physics

Though magnetic iron oxide nanoparticles (IONPs) are approved for clinical use as contrast agents for MR imaging in United States and Europe, and are widely used to label cells in research, the relationship between IONPs and mesenchymal stem cells (MSCs) is not fully addressed. Here the effects of consistently appeared γ-Fe2 O3 on the lineage commi...

Osteoarthritis (OA) is a chronic cartilage degeneration disease affecting total joint and with a wide global impact. Stem cell therapy has emerged as a potential stock for the treatment of OA. Exosomes are the mainstay of the paracrine function in stem cells, acting as an important mediator of intercellular communication. The purpose of this review...

Purpose Photodynamic therapy (PDT) is a non-invasive therapeutic modality that is used for several types of cancer and involves three essential elements (light, photosensitizer (PS), and oxygen). However, clinical PS is limited by the low yield of reactive oxygen species (ROS) and a long retention time. Therefore, developing a low-cost PS that can...

Intracellular calcium ion (Ca²⁺) in cytoplasm as an intracellular second messenger is involved in almost all important cellular activities of organisms. Generally its concentration ([Ca²⁺]i) is tested by live imaging followed image and data processes, in which much tedious and subjective manual work is involved. Here we show a computational approac...

Cartilage and joint damage easily degenerates cartilage and turns into osteoarthritis (OA), which seriously affects human life and work, and has no cure currently. The temporal and spatial changes of multiple microenvironments upon the damage of cartilage and joint are noticed, including the emergences of inflammation, bone remodeling, blood vessel...

An effective chemotherapy through promoting drug transport in solid tumor is our concern here to avoid surgery and its side effects to our bodies. A drug delivery system, TXT‐MNT‐hydrogel, is constructed using temperature sensitive hydrogel nanoparticles and hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) to co‐deliver mannitol (MNT) and taxotere (TXT). TXT...

Background: Liver sinusoidal endothelial cells (LSECs) display unique fenestrated morphology. Alterations in the size and number of fenestrae play a crucial role in the progression of various liver diseases. While their features have been visualized using atomic force microscopy (AFM), the in situ imaging methods and off-line analyses are further r...

Due to the ability to induce the generation of reactive oxygen species (ROS) under light irradiation, ZnO nanoparticles show great potential in photodynamic therapy (PDT). Photo-triggered ROS production by ZnO nanoparticles and the resulting phototoxicity are efficient in killing cancer cells. This review highlights the recent exciting progress on...

We have previously demonstrated that the rate of fluid shear stress (ΔSS) can manipulate the fate of mesenchymal stem cells (MSCs) to osteogenic or chondrogenic cells. However, whether ΔSS is comparable to other two means of induction medium and substrate stiffness that have been proven to be potent in differentiation control is unknown. In this st...

Neutrophil (PMN) accumulation on liver sinusoidal endothelial cells (LSECs) is crucial to pathogen clearance and tissue damage in the liver sinusoids and controlled by a series of adhesion molecules expressed on the surface of PMNs and LSECs. The role of lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1) in this proce...

Face to the limited repair capability of cartilage, we intended to find out signaling responsible for its matrix synthesis. Since spontaneous calcium response likes a label of cell status, here it was mapped in fresh and 24 h cultured in situ chondrocytes under oxygen tensions of 20%, 5% and 1% as well as mimic hypoxia conditions. The calcium sourc...

Cancer is a leading fatal disease worldwide. To increase its therapeutic efficiency, more effective with less side effect and patient acceptable administration approach is expected. Moreover, modification of tumor microenvironment is proved to be operative recently. In this paper, a nanocarrier named LDEDDS was developed for intelligent tropical ad...

The aim of this work was to study the high-titer L-lactic acid production from cellulosic waste using Rhizopus oryzae. The tobacco waste water-extract (TWE) added with 5 g/L glucose and 0.1 g/L vitamin C was optimized as pre-culture medium for Rhizopus oryzae. Results found that compared to traditional pre-culture medium, it improved xylose consump...

Manipulation of genes in human embryonic stem cells (hESCs) is imperative for their highly potential applications; however, the transduction efficiency remains very low. Although existing evidences revealed the type, size and zeta potential of vector affect gene transfection efficiency in cells, the systematic study in hESCs remains scarce. In this...

The effective regulation of fluid shear stress (FSS) on the lineage specification of mesenchymal stem cells (MSCs) remains to be addressed. We hypothesized that when MSCs are recruited to musculoskeletal system following stimulation, their differentiation into osteogenic or chondrogenic cells is directed by the rate of FSS (ΔSS) through modulation...

Low density lipoprotein (LDL)-apheresis therapy, which directly removes LDL from plasma by LDL-adsorbents in vitro is found to be clinically effective and safe to lower the LDL content in blood to prevent cardiovascular disease. Thus, developing excellent LDL adsorbents are becoming more and more attractive. Herein, functional Fe3O4@ZnO core-shell...

Although urethral carcinoma has a low incidence, it suffers from a poor curative rate for the low retention of medicine around urethra. In the present study, we developed a kind of magnetic targeting perfusion chemotherapy to detain the chemotherapeutic drugs. Docetaxel (TXT) grafted magnetic nanoparticles, of which size was around 40 nm, were obta...

In order to improve the therapeutic efficiency and reduce the side effects on nonpathological cells and tissues, targeting drug delivery systems have gained more and more attraction. Here, we report a novel dual-targeting drug delivery system for ovarian cancer therapy. The inner core was made of iron oxide (Fe3O4) nanoparticles, synthesized by co-...

The pericellular matrix (PCM), a thin coating surrounding nearly all mammalian cells, plays a critical role in many cell-surface phenomena. In osteocytes, the PCM is believed to control both "outside-in" (mechanosensing) and "inside-out" (signaling molecule transport) processes. However, the osteocytic PCM is challenging to study in situ because it...

The underlying cellular mechanism of anabolic effect recovered by inserting rest is not fully understood. In this work, we studied the role of F-actin regulated mechanosensitive channel(s) re-activation in mechanosensitivity modulation in vitro. Results showed that steady fluid shear stress (sFSS) stimulation with 30-min rest period was more potent...

The effect of prostaglandin E2 (PGE2) on bone mass has been well-established in vivo. Previous studies have showed that PGE2 increases differentiation, proliferation, and regulates cell morphology through F-actin stress fiber in statically cultured osteoblasts. However, the effect of PGE2 on osteoblasts in the presence of fluid shear stress (FSS),...

The present study reports a UV and dark-triggered highly intelligent drug delivery system for skin protection. ZnO nanoparticles (NPs), a UV filter, were synthesized and characterized to be the carrier for benzophenone-3 (Bp-3), a UV-absorption medicine, by varying the molar ratio of ZnO NPs to Bp-3 ranging from 300 : 1 to 20 : 1. The drug release...

We find that the empirical volatilities of corporate bond and CDS returns are higher than implied by equity return volatilities and the Merton model. This excess volatility may arise because structural models inadequately capture either fundamentals or illiquidity. Our evidence supports the latter explanation. We find little relation between excess...

Osteocytes, the most abundant cells in bone, are critical in maintaining tissue homeostasis and orchestrating bone's mechanical adaptation. Osteocytes depend upon load-induced convection within the lacunar-canalicular system (LCS) to maintain viability and to sense their mechanical environment. Using the fluorescence recovery after photobleaching (...

As a growth repair factor, mechano-growth factor (MGF) and its 24 amino acid peptide analogs corresponding to the unique C-terminal E-domain (MGF-Ct24E) positively regulate bone regeneration. MGF-Ct24E was introduced into the poly(D, L-lactic acid) (PDLLA) to improve bone regeneration in our previous study. MGF-Ct24E-grafted PDLLA was chemically ch...

Mechano-growth factor (MGF) is an alternative splicing variant of Insulin-like growth factor I. MGF and its 24 amino acid peptide analog corresponding to the unique C-terminal E-domain (MGF-Ct24E) are the positive regulator for tissue regenesis in bone. A novel biomimetic poly(D, L-lactic acid) (PDLLA) modification was designed and synthesized base...

Growing evidence shows that osteocytes, the most abundant bone cells, serve as the primary sensory cells that detect external mechanical forces [1], enabling the bone to adapt its mass and structure to meet its environmental requirements and to fulfill its weight bearing functions [2]. Although the cellular and molecular mechanisms of such adaptati...

Targeted drug delivery requires novel biodegradable, specific binding systems with longer circulation time. The aim of this study was to prepare biotinylated poly(lactic acid) (PLA) nanoparticles (NPs) which can meet regular requirements as well conjugate more biotins in the polymer to provide better binding with streptavidin. A biotin-graft-PLA wa...

The contact angle comparison of biotin-graft-poly(lactic acid) (A) and poly(ethylene glycol)-graft-poly(lactic acid) (B).

Differential scanning calorimetry curves of biotin-graft-poly(lactic acid) (A) and poly(ethylene glycol)-graft-poly(lactic acid) (B).

Osteoarthritis (OA) is a degenerative joint disease and one of the leading causes of disability in the United States and across the world. As a disease of the whole joint, OA exhibits a complicated etiology with risk factors including, but not limited to, ageing, altered joint loading, and injury. Subchondral bone is hypothesized to be involved in...

Non-linearity is an important consideration in many problems of finance and economics, such as pricing securities and solving equilibrium models. This paper provides analytical treatment of a general class of nonlinear transforms for processes with tractable conditional characteristic functions, which extends existing results on characteristic func...

We focus on the short sale ban of 2008 to examine the interaction between the price discovery in banned stocks and the trading of options and CDS. Within the sample of banned stocks with exchange traded options, stocks whose put-call ratios are in the top quintile underperform the middle group by 2.13% and 4.01% over the next three-and five-day ret...

This study concerns the encapsulation and controlled release of both hydrophobic and hydrophilic medications with one polymer, which are delivered together as a combined therapy to treat diseased tissue. To test our hypothesis that the novel PEG-graft-PLA (PEG, polyethylene glycol; PLA, polylactic acid) can deliver both the hydrophobic and hydrophi...

This paper examines the liquidity of corporate bonds and its asset-pricing implications using a novel measure of illiquidity based on the magnitude of transitory price move- ments. Using transaction-level data for a broad cross-section of corporate bonds from 2003 through 2007, we find the illiquidity in corporate bonds to be significant, sub- stan...

It is well accepted that osteoblasts respond to fluid shear stress (FSS) depending on the loading magnitude, rate, and temporal profiles. Although in vivo observations demonstrated that bone mineral density changes as the training intensity gradually increases/decreases, whether osteoblasts perceive such slow temporal changes in the strength of sti...

This paper examines the connection among corporate bonds, stocks, and Treasury bonds under the Merton model with stochastic interest rate, focusing in particular on the volatility of corporate bonds and its connection to the equity volatility of the same firm and the Treasury bond volatility. For a broad cross-section of corporate bonds from 2002 t...

seminar and symposium participants at the Hong Kong University of Science and Technology. We bear full responsibility for any errors. The financial support from a Hong Kong RGC Research Grant (Project # 642908) is gratefully acknowledged.

We propose a broad measure of liquidity for the overall financial market by exploiting its connection with the amount of arbitrage capital in the market and the potential impact on price deviations in US Treasurys. When arbitrage capital is abundant, we expect the arbitrage forces to smooth out the Treasury yield curve and keep the dispersion low....

Subchondral bone and articular cartilage play complementary roles in load bearing of the joints. Although the biomechanical coupling between subchondral bone and articular cartilage is well established, it remains unclear whether direct biochemical communication exists between them. Previously, the calcified cartilage between these two compartments...

This is an experimental study in the realm of physiology inquiring about the effect of pulsatile fluid flow shear stress on the proliferation, differentiation and functions of osteoblasts;the objective is to validate the important effect of fluid flow shear stress on the mechanics adaptability of bone tissue. The osteoblasts derived from Wistar rat...

This paper mainly presents two approaches for image retrieval. There is some faintness in color locating in quantification boundary when image color is quantized. The membership function in fuzzy set theory can describe the fuzzy transition preferably. In this paper, the membership function in HSI color space is adopted to solve the problem above....

Solute transport through the bone lacunar-canalicular system is believed to be essential for osteocyte survival and function. We have developed an approach that permits direct measurement of real-time solute movement in intact bones by using fluorescence recovery after phtobleaching (FRAP) technology [1]. The movement of vitally injected fluorescen...

This paper investigates informed trading on stock volatility in the option market. We construct non-market maker net demand for volatility from the trading volume of individual equity options and find that this demand is informative about the future realized volatility of underlying stocks. We also find that the impact of volatility demand on optio...

This paper explores the nature of default arrival and recovery implicit in the term structures of sovereign "CDS" spreads. We argue that term structures of spreads reveal not only the arrival rates of credit events , but also the loss rates given credit events. Applying our framework to Mexico, Turkey, and Korea, we show that a single-factor model...

We study the nature of sovereign credit risk using an extensive sample of CDS spreads for 26 developed and emerging-market countries. Sovereign credit spreads are surprisingly highly correlated, with just three principal components accounting for more than 50 percent of their variation. Sovereign credit spreads are generally more related to the U.S...

A new poly(ethylene glycol) (PEG)-modified poly(D,L-lactic acid) (PLA) was synthesized by grafting maleic anhydride onto PLA and subsequently amidating with O,O'-bis-(2-aminopropyl) polypropylene glycol-block-polyethylene oxide-block-polypropylene glycol (H2N-PEG-NH2, Mw: 600). Its structure was confirmed by FTIR, DSC, 1H NMR, GPC, and ninhydrin te...

We study the nature of sovereign credit risk using an extensive set of sovereign CDS data. We find that the majority of sovereign credit risk can be linked to global factors. A single principal component accounts for 64 percent of the variation in sovereign credit spreads. Furthermore, sovereign credit spreads are more related to the US stock and h...

seminar participants at MIT and the University of Oklahoma for their comments. We also thank Ted Reeve for providing us with his derivative surveys of gold mining firms, and Sridhar Gogineni and Leung Kam Ming for excellent research assistance. We are responsible for any remaining errors.

Insulin-like growth factor 1 (IGF-1) promotes osteoblasts differentiation and bone formation, and its expression is induced by mechanical stretch, thus IGF-1 has been considered an effector molecule that links mechanical stimulation and local tissue responses. In this study, a mechanical stretching device was designed to apply physiological level s...

We present strong evidence that option trading volume contains information about future stock prices. Taking advantage of a unique data set, we construct put-call ratios from option volume initiated by buyers to open new positions. Stocks with low put-call ratios outperform stocks with high put-call ratios by more than 40 basis points on the next d...

This paper examines the recent period of relatively low credit spreads in Japan, with particular emphasis on the marketfs assessments of the credit risks of large Japanese banks implicit in the prices of credit derivatives. We extract the market-price implied likelihood of a credit event in the future, and explore the nature of the default risk pre...

We present strong evidence that option trading volume contains information about future stock prices. Taking advantage of a unique data set, we construct put-call ratios from option volume initiated by buyers to open new positions. Stocks with low put-call ratios outperform stocks with high put-call ratios by more than 40 basis points on the next d...

We exploit the information in the options market to study the risk and risk premium variations around the Nasdaq bubble period. In particular, we investigate whether the dramatic rise and fall of the Nasdaq can be justified by changes in return risk, or there were corresponding unusual shifts in how investors price risks. We specify a model that ac...

The physiological reconstruction of bone is strictly dependent on bone resorption. Bone resorption is believed to be a complicated molecular reaction process that occurs in the microcircumstance of bone tissue. A lot of enzymes and factors take part in this process, yet there are not enough data with reference to the activation of osteoclast, resor...

This paper investigates the information in option volume for the future volatility of underlying stocks. Using a unique data set from the Chicago Board Options Exchange, we construct non-market maker net demand for volatility over the 1990 through 2001 period. We find that this demand possesses information about the future volatility of underlying...

A process of preparing bovine cortical bone in order to form materials suitable for biomedical xenograft implants was described. Fresh bone samples cut from the middiaphyseal region of bovine femora were obtained from a local slaughterhouse. The bovine bone collagen matrix (BBCM) of various shapes fabricated from bovine bone by defatting and deprot...

In the research field of bone tissue engineering, the interaction of osteoblast and substrate is pivotal and the adhesion of osteoblast to biomaterials is the basic condition. Firstly, osteoblast must adhere to biomaterials, then it can migrate, proliferate and differentiate. This paper introduces the proteins relating to the adhesion of osteoblast...

Endothelialization of artificial vascular graft is considered as one of the most promising methods to improve its antithrombotic ability and long-term patency. Endothelialization of artificial vascular graft includes harvesting endothelial cells, choosing some materials with better compliance and seeding endothelial cells. The methods such as immob...

Bioactivity of biomaterials was a new requirement, especially in tissue engineering and drug delivery. As a traditional used biomaterial, polylactide (PLA) had no bioactivity, of course, and it still had few reactive groups to introduce some bioactive molecules in its bulk. Here, we want to introduce carboxyl groups and amino groups in the side cha...

Biomedical materials are the biomaterials that, used in physiological system for diagnosis, treatment, plerosis or replacement of tissues and organs. Apoptosis, also known as PCD or ACD, is a normal physiological mechanism of cell in organism and a process of automatic cell death in which multicell organism modulates the development of organism and...

Mechanical forces regulate the function of bone cells. In this paper, the effects of cyclic stretching on osteoblasts derived from rat calvaria were studied at a magnitude occurring in physiological loaded bone tissue. A four-point bending apparatus was used to apply cyclic stretching on osteoblasts. Stretching at 500 microepsilon for 2-24 h result...

Atomic force microscope (AFM) is a powerful and novel tool to investigate the surface and submembranous structures of living cells under physiological conditions at high resolution, and has force measure at nano-Newton level. AFM can image and manipulate samples (single macromolecule, cells, and so on) at very high, sometimes atomic resolution by s...

How do risk-neutral return skews evolveover time and in the cross-section of individual stocks? We document the di#erential pricing of individual equity options versus the market index, and relate it to variations in the skew. The change-of-measure induced by marginalutility tilting of the physical density can introduce skews in the risk-neutral re...

Major events often trigger abrupt changes in stock prices and volatility. We study the implications of jumps in prices and volatility on investment strategies. Using the event-risk framework of Duffie, Pan, and Singleton (2000), we provide analytical solutions to the optimal portfolio problem. Event risk dramatically affects the optimal strategy. A...

To explore the preparative method and study the degradation characteristics of bone repair composite of DL-polylactic acid (PDLLA)/hydroxyapatite(HA)/decalcifying bone matrix (DBM) in vitro. An emulsion blend method was developed to prepare the composite of PDLLA/HA/DBM in weight ratio of PDLLA:HA:DBM = 1.5-2:1-1.5:1. The dynamic changes of weight,...

In this paper, we study the asset pricing implication of imprecise knowledge about rare events. Modeling rare events as jumps in the aggregate endowment, we explicitly solve the equilibrium asset prices in a pure-exchange economy with a representative agent who is averse not only to risk but also to model uncertainty with respect to rare events. Ou...

We study optimal investment strategies given investor access not only to bond and stock markets but also to the derivatives market. The problem is solved in closed form. Derivatives extend the risk and return tradeoffs associated with stochastic volatility and price jumps. As a means of exposure to volatility risk, derivatives enable non-myopic inv...

This paper examines the joint time series of the S&P 500 index and near-the-money short-dated option prices with an arbitrage-free model, capturing both stochastic volatility and jumps. Jump-risk premia uncovered from the joint data respond quickly to market volatility, becoming more prominent during volatile markets. This form of jump-risk premia...

We investigate whether the volatility risk premium is negative by examining the statistical properties of delta-hedged option portfolios (buy the option and hedge with stock). Within a stochastic volatility framework, we demonstrate a correspondence between the sign and magnitude of the volatility risk premium and the mean delta-hedged portfolio re...

This article provides several new insights into the economic sources of skewness. First, we document the differential pricing of individual equity options versus the market index, and relate it to variations in return skewness. Second, we show how risk aversion introduces skewness in the risk-neutral density. Third, we derive laws that decompose in...

This paper provides an analytical approximation for computing value at risk and other risk measures for portfolios that may include options and other derivatives with defaultable counterparties or borrowers. The risk setting is that of a classical multi-factor jump-diffusion for default intensities and asset returns, under which between-jump return...

An inherent risk facing investors in financial markets is that a major event may trigger a large abrupt change in stock prices and market volatility. This paper studies the implications of jumps in prices and volatility on investment strategies. Using the event-risk framework of Duffie, Pan, and Singleton, we provide an analytical solution to the o...

In the setting of affine' jump-diffusion state processes, this paper provides an analytical treatment of a class of transforms, including various Laplace and Fourier transforms as special cases, that allow an analytical treatment of a range of valuation and econometric problems. Example applications include fixed-income pricing models, with a role...

This paper examines the joint time series of the S&P 500 index and near-the-money short-dated option prices with an arbitrage-free model, capturing both stochastic volatility and jumps. Jump-risk premia uncovered from the joint data respond quickly to market volatility, becoming more prominent during volatile markets. This form of jump-risk premia...

This paper presents a model for asset returns incorporating both stochastic volatility and jump effects. The return process is driven by two types of randomness: small random shocks and large jumps. The stochastic volatility process is affected by both types of randomness in returns. Specifically, in the absence of large jumps, volatility is driven...

This article gives a broad and accessible overview of models of value at risk (WR), a popular measure of the market risk of a financial firm's "book," the list ofpositions in various instruments that expose the firm to financial risk. Roughly speaking, the value at risk o f a portfolio is the loss in market value over a given time period, such as o...

1 Abstract Although financial theory predicts a strong link between bond yields and bond option prices, recent research has had limited suc-cess at pricing both bonds and bond options using low-dimensional dynamic term structure models. In this paper I show that, with suffi-cient flexibility in the covariance structure of the risk factors and the m...

ABSTRACT We examine the pricing of credit protection in the rapidly growing credit- default swap market using an extensive data set provided by Citigroup. We fit a reduced-form model to corporate bond yields and solve for the credit-default swap premia they imply. We compare these implied credit- default swap premia to actual market premia. Implied...

ABSTRACT In theory, an investor can make infinite profits by taking unlimited posi- tions in an arbitrage. In reality, however, investors must satisfy margin requirements which completely change the economics of arbitrage. We derive the optimal investment policy for a risk-averse investor in a mar- ket where there are arbitrage opportunities. We sh...

This paper suggests a new state space approach to analysis of stock return predictability. Acknowledging that expected returns and expected dividends are unobservable, the Kalman filter technique is used to extract them from the observed history of realized dividends and returns. This approach explicitly accounts for the variation in expected divid...

This paper examines the connection between the return volatilities of credit market securities, equities, and Treasuries using a Merton model with stochastic interest rates. Focusing primarily on monthly bond and CDS returns, we find that the credit market exhibits volatility in excess of what the equity market and the Merton model suggest. In conj...