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G Shiu

Publications and source records attributed to G Shiu.

9 recordsLinked to original sources
PubMed2001

Three-family supersymmetric standardlike models from intersecting brane worlds.

We construct the first three family N = 1 supersymmetric string model with standard model gauge group SU(3)(C) x SU(2)(L) x U(1)(Y) from an orientifold of type IIA theory on T(6)/(Z(2) x Z(2)) and D6-branes intersecting at angles. In addition to the minimal supersymmetric standard model particles, the model contains right-handed neutrinos, a chiral (but anomaly-free) set of exotic multiplets, and extra vectorlike multiplets. We discuss some phenomenological features of this model.

Journal Article↗
PubMed1991

Validation of bioanalytical methods.

Validation of bioanalytical methods used to generate data for pharmacokinetic and bioavailability studies is approached by a variety of techniques and is subject to many different methods of interpretation. This Review puts the various techniques into perspective and discusses pitfalls which may occur in interpretation of validation data. Recovery studies, standardization techniques, and selectivity/specificity are discussed with regard to the intrinsic value of various techniques that are used in validation. Models used for analytical calibration curves are explained in terms of their validity and limitations, along with a presentation of the most common ways to validate the model. Analytical sensitivity and detection limits are presented and discussed with regard to the usefulness of the various definitions. Appropriate means of testing precision and accuracy, the most important factors in assessing method quality, are presented. Stability and ruggedness testing are discussed along with a presentation of ways to assess data acceptability on a daily run basis.

Biopharmaceutics↗
PubMed1972

Expression of fetal antigens in tumor cells.

The activities of sera that reacted specifically with the specific cell-surface antigens of polyoma or simian virus 40 tumors could only be inhibited by absorption of the sera with tumor cells transformed by the specific virus, and could not be removed by the absorption with cells from various fetal tissues nor with cells from other tumors. In contrasts, the antisera produced in male C3H/HeN mice by inoculation of irradiated, syngeneic fetal tissue of 1- to 2-weeks gestation, reacted with various tumor cells. The activities of these sera, when tested against cells from tumors induced by polyoma virus or simian virus 40, could also be removed by absorption with cells from tumors induced by viruses other than polyoma or simian virus 40, including leukemia cells induced by Gross virus (C58NT)D, Rauscher virus (RBL-5), and by dimethylbenzanthrene (EL. 4), and cells from mammary tumors (MM102), plasma-cell tumors (MPC-113), and fetal tissues. These results indicated that fetal antigens may be expressed in tumor cells, but they are different from tumor-specific antigens that are specific for a particular tumor or for tumors induced by a particular virus.

Animals↗
PubMed1969

Virus-induced sarcoma of mice: inhibition by a synthetic polyribonucleotide complex.

The availability of a potent inducer of interferon, the synthetic double-stranded RNA (poly I.poly C), prompted us to determine its possible prophylactic and/or therapeutic effect on virus-induced sarcomas of mice. When treatment was begun prior to virus inoculation and repeated on alternate days, the majority of NIH Swiss mice inoculated with Moloney or Friend pseudotypes of Moloney murine sarcoma virus failed to develop tumors. Other experiments suggested that repeated injections initiated even after the establishment of tumor nodules were also effective. Mice injected on the day of birth with poly I.poly C develop high titers of interferon. The evidence favors, but does not establish, the interpretation that the observed tumor inhibition is mediated through the induction of endogenous interferon. These experiments demonstrate that treatment with poly I.poly C is followed by a regression of established murine sarcoma infection in mice.

Animals↗