Massive Graviton Spectra in Supergravity

Development of a unified theory of physics would pave the way for new research and technology development for many years to come. Unfortunately, the two best current theories explaining nature, the Standard Model of particle physics and general relativity, do not seem to be compatible, requiring the development of more complicated models which contains both of these at their respective limits. Supergravities are one set of theories which may, at least in part, provide hints as to how it may be possible to unify physics into a single model. This research project follows from a line of investigation which the primary investigator and collaborators have been pursuing for the past several years exploring the properties of supergravity. The main goal of this project was attempting to confirm whether or not the mass spectra of gravitons are common among different theories of supergravity, and if not to find any properties which are universal, in order to improve understanding of super-gravities as a whole. Our research group examined 8 sectors of symmetry within 3 different supergravity theories and found that these mass spectra are not universal, but that there do exist relations which are. We then found a way to write all the mass spectra we investigated and these relations we found in a universal way using the language of general relativity

Universal properties of Kaluza-Klein gravitons

Vacua of different gaugings of D = 4 N = 8 supergravity that preserve the same supersymmetries and bosonic symmetry tend to exhibit the same universal mass spectrum within their respective supergravities. For AdS4 vacua in gauged supergravities that arise upon consistent truncation of string/M-theory, we show that this universality is lost at higher Kaluza-Klein levels. However, universality is still maintained in a milder form, at least in the graviton sector: certain sums over a finite number of states remain universal. Further, we derive a mass matrix for Kaluza-Klein gravitons which is valid for all the AdS4 vacua in string/M-theory that uplift from the gaugings of D = 4 N = 8 supergravity that we consider. The mild universality of graviton mass sums is related to the trace of this mass matrixKD, PN and OV are supported by the NSF grant PHY-1720364. GL is supported by an FPI-UAM predoctoral fellowship. GL and OV are partially supported by grants SEV-2016-0597 and PGC2018-095976-B-C21 from MCIU/AEI/FEDER, U

Clickable modular polysaccharide nanoparticles for selective cell-targeting

A therapeutic nanocarrier capable of cell targeting has the potential to reduce off-target effects of otherwise effective drugs. Nanoparticle surface modification can be tailored for specific cells, however multistep surface modification can prove slow and difficult for a variety of cell types. Here, we designed drug carrying polysaccharide based nanoparticles with a layered structure for clickable surface modification. The center of nanoparticle was composed of cationic macromer (e.g., poly-L-lysine) and anionic polysaccharide (e.g., heparin). Furthermore, a ‘clickable’ polysaccharide was installed on the surface of the nanoparticles to permit a wide range of bioconjugation via norbornene-tetrazine click chemistry. The utilities of these layered nanoparticles were demonstrated via enhanced protein sequestration, selective cell targeting (via PEGylation or altering polysaccharide coating), as well as loading and release of chemotherapeutic. The drug-loaded nanocarriers proved cytotoxic to J774A.1 monocytes and MOLM-14 leukemia cells

Clickable modular polysaccharide nanoparticles for selective cell-targeting

A therapeutic nanocarrier capable of cell targeting has the potential to reduce off-target effects of otherwise effective drugs. Nanoparticle surface modification can be tailored for specific cells, however multistep surface modification can prove slow and difficult for a variety of cell types. Here, we designed drug carrying polysaccharide based nanoparticles with a layered structure for clickable surface modification. The center of nanoparticle was composed of cationic macromer (e.g., poly-L-lysine) and anionic polysaccharide (e.g., heparin). Furthermore, a ‘clickable’ polysaccharide was installed on the surface of the nanoparticles to permit a wide range of bioconjugation via norbornene-tetrazine click chemistry. The utilities of these layered nanoparticles were demonstrated via enhanced protein sequestration, selective cell targeting (via PEGylation or altering polysaccharide coating), as well as loading and release of chemotherapeutic. The drug-loaded nanocarriers proved cytotoxic to J774A.1 monocytes and MOLM-14 leukemia cells

Initial Laparotomy Versus Peritoneal Drainage in Extremely Low Birthweight Infants With Surgical Necrotizing Enterocolitis or Isolated Intestinal Perforation: A Multicenter Randomized Clinical Trial.

ObjectiveThe aim of this study was to determine which initial surgical treatment results in the lowest rate of death or neurodevelopmental impairment (NDI) in premature infants with necrotizing enterocolitis (NEC) or isolated intestinal perforation (IP).Summary background dataThe impact of initial laparotomy versus peritoneal drainage for NEC or IP on the rate of death or NDI in extremely low birth weight infants is unknown.MethodsWe conducted the largest feasible randomized trial in 20 US centers, comparing initial laparotomy versus peritoneal drainage. The primary outcome was a composite of death or NDI at 18 to 22 months corrected age, analyzed using prespecified frequentist and Bayesian approaches.ResultsOf 992 eligible infants, 310 were randomized and 96% had primary outcome assessed. Death or NDI occurred in 69% of infants in the laparotomy group versus 70% with drainage [adjusted relative risk (aRR) 1.0; 95% confidence interval (CI): 0.87-1.14]. A preplanned analysis identified an interaction between preoperative diagnosis and treatment group (P = 0.03). With a preoperative diagnosis of NEC, death or NDI occurred in 69% after laparotomy versus 85% with drainage (aRR 0.81; 95% CI: 0.64-1.04). The Bayesian posterior probability that laparotomy was beneficial (risk difference <0) for a preoperative diagnosis of NEC was 97%. For preoperative diagnosis of IP, death or NDI occurred in 69% after laparotomy versus 63% with drainage (aRR, 1.11; 95% CI: 0.95-1.31); Bayesian probability of benefit with laparotomy = 18%.ConclusionsThere was no overall difference in death or NDI rates at 18 to 22 months corrected age between initial laparotomy versus drainage. However, the preoperative diagnosis of NEC or IP modified the impact of initial treatment