399 research outputs found
Caught in the Headlights: Revising the Road Kill Hypothesis of Antebellum Illinois Bank Failures
Illinois had a dismal free banking experience, with over 80% of its free banks failing by the start of the Civil War. Researchers agree that a dramatic change in bond prices was the catalyst, and some have shown that the riskiest banks, ex ante, were the most likely to fail. This study examines how Illinois free banks adjusted their portfolios in the face of increased political and financial risks prior to Abraham Lincoln’s election as president. Lincoln’s nomination in May 1860 and the Democratic Party schism in June 1860 raised the likelihood of secession and the potential for a significant decline in Southern bond prices. Given this heightened risk, did free bankers reduce their exposure to such a decline? In general, it appears that the free bankers took risks commensurate with expected returns and the uncertain political climate, purchased the most readily available bonds, and had sufficient backing to withstand a moderate decline in Southern bond prices. The dramatic price decline soon after the election appears to have caught many banks by surprise, like a deer caught in the headlights
Functionalized Poly(3-hexylthiophene)s via Lithium–Bromine Exchange
Poly(3-hexylthiophene) (P3HT) is one of the most extensively investigated conjugated polymers and has been employed as the active material in many devices including field-effect transistors, organic photovoltaics and sensors. As a result, methods to further tune the properties of P3HT are desirable for specific applications. Herein, we report a facile postpolymerization modification strategy to functionalize the 4-position of commercially available P3HT in two simple steps–bromination of the 4-position of P3HT (Br–P3HT) followed by lithium−bromine exchange and quenching with an electrophile. We achieved near quantitative lithium–bromine exchange with Br–P3HT, which requires over 100 thienyl lithiates to be present on a single polymer chain. The lithiated-P3HT is readily combined with functional electrophiles, resulting in P3HT derivatives with ketones, secondary alcohols, trimethylsilyl (TMS) group, fluorine, or an azide at the 4-position. We demonstrated that the azide-modified P3HT could undergo Cu-catalyzed or Cu-free click chemistry, significantly expanding the complexity of the structures that can be appended to P3HT using this method.National Science Foundation (U.S.) (ECCS-0939514
Zinc Phthalocyanine−Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics and Photoelectrochemical Cell Preparation
Graphene exfoliation upon tip sonication in o-‐DCB was accomplished. Then, covalent grafting of (2-‐ aminoethoxy)(tri-‐tert-‐butyl) zinc phthalocyanine (ZnPc), to exfoliated graphene sheets was achieved. The newly formed ZnPc-‐graphene hybrid material was found soluble in common organic solvents without any precipitation for several weeks. Application of diverse spectroscopic techniques verified the successful formation of ZnPc-‐graphene hybrid materi-‐ al, while thermogravimetric analysis revealed the amount of ZnPc loading onto graphene. Microscopy analysis based on AFM and TEM was applied to probe the morphological characteristics and to investigate the exfoliation of graphene sheets. Efficient fluorescence quenching of ZnPc in the ZnPc-‐graphene hybrid material suggested that photoinduced events occur from the photoexcited ZnPc to exfoliated graphene. The dynamics of the photoinduced electron transfer was
evaluated by femtosecond transient absorption spectroscopy, thus, revealing the formation of transient species such as ZnPc+ yielding the charge-‐separated state ZnPc•+–graphene•–. Finally, the ZnPc-‐graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO2 films (OTE/SnO2), which exhibited sta le and reproducible photocurrent responses and the incident photon-‐to-‐current conversion efficien-‐ cy was determine
Why do banks promise to pay par on demand?
We survey the theories of why banks promise to pay par on demand and examine evidence about
the conditions under which banks have promised to pay the par value of deposits and banknotes on
demand when holding only fractional reserves. The theoretical literature can be broadly divided into four
strands: liquidity provision, asymmetric information, legal restrictions, and a medium of exchange. We
assume that it is not zero cost to make a promise to redeem a liability at par value on demand. If so, then
the conditions in the theories that result in par redemption are possible explanations of why banks
promise to pay par on demand. If the explanation based on customers’ demand for liquidity is correct,
payment of deposits at par will be promised when banks hold assets that are illiquid in the short run. If
the asymmetric-information explanation based on the difficulty of valuing assets is correct, the
marketability of banks’ assets determines whether banks promise to pay par. If the legal restrictions
explanation of par redemption is correct, banks will not promise to pay par if they are not required to do
so. If the transaction explanation is correct, banks will promise to pay par value only if the deposits are
used in transactions. After the survey of the theoretical literature, we examine the history of banking in
several countries in different eras: fourth-century Athens, medieval Italy, Japan, and free banking and
money market mutual funds in the United States. We find that all of the theories can explain some of the
observed banking arrangements, and none explain all of them
A phase-II study with idarubicin, etoposide and prednisone (IVPP), in patients with refractory or early relapsed intermediate or high grade non-Hodgkin's lymphoma
Haematologic
Validating the meta-analytical results on MDM2, CASP8, XRCC3 polymorphisms and breast cancer risk: examination of Hardy–Weinberg Equilibrium
Eligible and not eligible studies in the recent meta-analysis about p53 polymorphism and breast cancer risk
Second malignancies following treatment for Hodgkin's disease: a Greek experience
The risk and the type of second malignancies (SM) developing in 217 treated Hodgkin's disease (HD) patients were studied. The median age of the patients was 35 years (range 14-83) and the M/F ratio 1.8. Treatment consisted of radiotherapy alone (24 patients, 11%), chemotherapy alone (96 patients, 44.3%), or a combination of both modalities (43 patients, 19.8%), while 54 patients (24.9%) received salvage treatment. The median follow-up time was 67 months (range 12-224). Ten patients developed a SM with a 5-year and 10-year actuarial risk of 3.3% and 5.4%, respectively. There were 3 cases of ANLL and MDS (actuarial risk of 2.4% at 6 years), 1 case of non-Hodgkin's lymphoma and 6 cases of solid tumors (actuarial risk of 2.4% at 6 years). The risk of developing SM was higher in males and older patients (> 40 years). SM represent a serious late side effect of successful treatment for HD. The possibility of developing a SM must be taken into consideration in the initial treatment of the disease.Haematologic
Does race modify the association between CYP1B1 Val432Leu polymorphism and breast cancer risk? A critical appraisal of a recent meta-analysis
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