Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
1,906
result(s) for
"Williams, Gregory A."
Sort by:
Multiphase design of autonomic self-healing thermoplastic elastomers
by
Williams, Gregory A.
,
Kushner, Aaron M.
,
Guan, Zhibin
in
639/638/298/303
,
639/638/455
,
639/638/541
2012
The development of polymers that can spontaneously repair themselves after mechanical damage would significantly improve the safety, lifetime, energy efficiency and environmental impact of man-made materials. Most approaches to self-healing materials require the input of external energy, healing agents, solvent or plasticizer. Despite intense research in this area, the synthesis of a stiff material with intrinsic self-healing ability remains a key challenge. Here, we show a design of multiphase supramolecular thermoplastic elastomers that combine high modulus and toughness with spontaneous healing capability. The designed hydrogen-bonding brush polymers self-assemble into a hard–soft microphase-separated system, combining the enhanced stiffness and toughness of nanocomposites with the self-healing capability of dynamic supramolecular assemblies. In contrast to previous self-healing polymers, this new system spontaneously self-heals as a single-component solid material at ambient conditions, without the need for any external stimulus, healing agent, plasticizer or solvent.
Polymer materials that could spontaneously heal like tissues in living systems would significantly improve the safety, lifetime, energy efficiency and environmental impact of man-made materials. Now, a general multiphase design of autonomous self-healing elastomeric materials that do not require the input of external energy or healing agents is reported.
Journal Article
Long-Term Endocrine and Exocrine Insufficiency After Pancreatectomy
by
Anderson, Blaire
,
Liu, Jingxia
,
Doyle, Majella M. B.
in
Exocrine Pancreatic Insufficiency - epidemiology
,
Exocrine Pancreatic Insufficiency - etiology
,
Female
2019
Purpose
To identify peri-operative risk factors and time to onset of pancreatic endocrine/exocrine insufficiency.
Methods
We retrospectively analyzed a single institutional series of patients who underwent pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) between 2000 and 2015. Endocrine/exocrine insufficiencies were defined as need for new pharmacologic intervention. Cox proportional modeling was used to identify peri-operative variables to determine their impact on post-operative pancreatic insufficiency.
Results
A total of 1717 patient records were analyzed (75.47% PD, 24.53% DP) at median follow-up 17.88 months. Average age was 62.62 years, 51.78% were male, and surgery was for malignancy in 74.35% of patients. Post-operative endocrine insufficiency was present in 20.15% (
n
= 346). Male gender (
p
= 0.015), increased body mass index (BMI) (
p
< 0.001), tobacco use (
p
= 0.011), family history of diabetes (DM) (
p
< 0.001), personal history of DM (
p ≤
0.001), and DP (
p ≤
0.001) were correlated with increased risk. Mean time to onset was 20.80 ± 33.60 (IQR: 0.49–28.37) months. Post-operative exocrine insufficiency was present in 36.23% (
n
= 622). Race (
p
= 0.014), lower BMI (
p
< 0.001), family history of DM (
p
= 0.007
)
, steatorrhea (
p
< 0.001), elevated pre-operative bilirubin (
p
= 0.019), and PD (
p ≤
0.001) were correlated with increased risk. Mean time to onset was 14.20 ± 26.90 (IQR: 0.89–12.69) months.
Conclusions
In this large series of pancreatectomy patients, 20.15% and 36.23% of patients developed post-operative endocrine and exocrine insufficiency at a mean time to onset of 20.80 and 14.20 months, respectively. Patients should be educated regarding post-resection insufficiencies and providers should have heightened awareness long-term.
Journal Article
In situ ultra-small-angle X-ray scattering study under uniaxial stretching of colloidal crystals prepared by silica nanoparticles bearing hydrogen-bonding polymer grafts
by
Sato, Masugu
,
Takahara, Atsushi
,
Higaki, Yuji
in
Chemical properties
,
colloidal crystals
,
Diffraction
2016
A molded film of single-component polymer-grafted nanoparticles (SPNP), consisting of a spherical silica core and densely grafted polymer chains bearing hydrogen-bonding side groups capable of physical crosslinking, was investigated by in situ ultra-small-angle X-ray scattering (USAXS) measurement during a uniaxial stretching process. Static USAXS revealed that the molded SPNP formed a highly oriented twinned face-centered cubic (f.c.c.) lattice structure with the [11−1] plane aligned nearly parallel to the film surface in the initial state. Structural analysis of in situ USAXS using a model of uniaxial deformation induced by rearrangement of the nanoparticles revealed that the f.c.c. lattice was distorted in the stretching direction in proportion to the macroscopic strain until the strain reached 35%, and subsequently changed into other f.c.c. lattices with different orientations. The lattice distortion and structural transition behavior corresponded well to the elastic and plastic deformation regimes, respectively, observed in the stress–strain curve. The attractive interaction of the hydrogen bond is considered to form only at the top surface of the shell and then plays an effective role in cross-linking between nanoparticles. The rearrangement mechanism of the nanoparticles is well accounted for by a strong repulsive interaction between the densely grafted polymer shells of neighboring particles.
Journal Article
Increased Morbidity and Mortality After Hepatectomy for Colorectal Liver Metastases in Frail Patients is Largely Driven by Worse Outcomes After Minor Hepatectomy: It’s Not “Just a Wedge”
2022
BackgroundFrailty is associated with postoperative mortality, but its significance after hepatectomy for colorectal liver metastases (CRLM) is poorly defined. This study evaluated the impact of frailty after hepatectomy for CRLM.MethodsThe study identified 8477 patients in National Surgical Quality Improvement Program databases from 2014 to 2019 and stratified them by frailty score using the risk analysis index as very frail (>90th percentile), frail (75th–90th percentile), or non-frail (< 75th percentile). Multivariate regression models determined the impact of frailty on perioperative outcomes, including by the extent of hepatectomy.ResultsThe procedures performed were 2752 major hepatectomies (left hepatectomy, right hepatectomy, trisectionectomy) and 5725 minor hepatectomies (≤2 segments) for 870 (10.3%) very frail, 1680 (19.8%) frail, and 5927 (69.9%) non-frail patients. Postoperatively, the very frail and frail patients experienced more complications (very frail [41.8%], frail [35.1%], non-frail [31.0%]), which resulted in a longer hospital stay (very-frail [5.7 days], frail [5.8 days], non-frail [5.1 days]), a higher 30-day mortality (very-frail [2.2%], frail [1.3%], non-frail [0.5%]), and more discharges to a facility (very frail [6.8%], frail [3.7%], non-frail [2.6%]) (p < 0.05) although they underwent similarly extensive (major vs. minor) hepatectomies. In the multivariate analysis, frailty was independently associated with complications (very-frail [odds ratio {OR}, 1.70], frail [OR, 1.25]) and 30-day mortality (very-frail [OR, 4.24], frail [OR, 2.41]) (p < 0.05). After minor hepatectomy, the very frail and frail patients had significantly higher rates of complications and 30-day mortality than the non-frail patients, and in the multivariate analysis, frailty was independently associated with complications (very frail [OR, 1.97], frail [OR, 1.27]) and 30-day mortality (very frail [OR, 6.76], frail [OR, 3.47]) (p < 0.05) after minor hepatectomy.ConclusionsFrailty predicted significantly poorer outcomes after hepatectomy for CRLM, even after only a minor hepatectomy.
Journal Article
Cause and outcome of aborting a difficult laparoscopic cholecystectomy due to severe inflammation: a study of operative notes
by
Hawkins, William G
,
Williams, Gregory A
,
Hammill, Chet W
in
Cholecystectomy
,
Dissection
,
Gallbladder
2022
BackgroundUpon encountering a difficult cholecystectomy in which, after a reasonable trial of dissection, anatomical identification has not been attained due to severe inflammation, and the risk of additional dissection is deemed to be hazardous, “bail-out” strategies are encouraged safety valves. One strategy is to abort the cholecystectomy and refer the patient to a HPB center for further management.MethodsA retrospective review was conducted of cholecystectomies performed by HPB surgeons at our center between 2005 and 2019. We identified 63 patients who had an aborted cholecystectomy because of acute or chronic cholecystitis and were referred for additional care. Of these, operative notes and other clinical records were available for 43 patients who were included in this study.Results42 cholecystectomies (98%) were started laparoscopically. 25 patients (58%) had chronic cholecystitis, and 18 (42%) had acute cholecystitis. 40 cases (93%) fell into the highest level of difficulty on the Nassar scale (Grade 4). Procedures were aborted at the following stages of dissection: in 10 patients (23%), none of the gallbladder was identified; in another 11 (26%), only the dome of gallbladder was identified; the body of the gallbladder was exposed in 13 (30%); and dissection of the hepatocystic triangle was attempted unsuccessfully in 9 (21%). Following referral to our center, 30 patients (70%) were managed with total cholecystectomy while in 13 cases (30%), subtotal cholecystectomy was performed.ConclusionAborting cholecystectomy and referring the patient to an HPB center is rarely needed but is an effective bail-out strategy for general surgeons encountering highly difficult operative conditions due to inflammation.
Journal Article
ASO Visual Abstract: Increased Morbidity and Mortality After Hepatectomy for Colorectal Liver Metastases in Frail Patients is Largely Driven by Worse Outcomes After Minor Hepatectomy: It is Not “Just a Wedge”
by
Hawkins, William G
,
Williams, Gregory A
,
Leigh, Natasha
in
Hepatectomy
,
Metastases
,
Morbidity
2022
Journal Article
Extending Enhanced Recovery after Surgery Protocols to the Post-Discharge Setting: A Phone Call Intervention to Support Patients after Expedited Discharge after Pancreaticoduodenectomy
by
Takchi, Rony
,
Stoentcheva, Tina
,
Brauer, David
in
Activities of daily living
,
Aged
,
Clinical outcomes
2020
The goal of this pilot study was to track patient outcomes after an expedited discharge after enhanced recovery after surgery (ERAS) pathway for pancreaticoduodenectomy (PD). A quantitative content analysis approach was used. All PD patients in a single academic medical center between February 2017 and June 2018 were called twice by specialized physician extenders after discharge. A semi-structured interview approach was used to identify patient's symptoms or concerns, proactively educate them, and provide outpatient management when indicated. A detailed narrative of the conversation was documented. Ninety patients (mean age 66.3; 58.1% males) were included in the study. Of all, 88.9 per cent of the patients received follow-up phone calls in accordance with our PD ERAS protocol. Among the 80 patients called, 71 (88.8%) reported at least one symptom, issue, or self-care need. The most common issues involved bowel movements and nutrition. A total of 147 interventions were performed to address patient needs including medication management, local care coordination, and outpatient referral to a healthcare provider. The intervention led to the identification of 15 patients for earlier evaluation. This identification was associated with the total number of reported symptoms (X2 = 15.6, P = 0.004). Most patients require additional care after discharge after traditional ERAS pathways. ERAS transitional care protocols uncovered an unmet need for additional patient support after PD.
Journal Article
Composite Length of Stay, An Outcome Measure of Postoperative and Readmission Length of Stays in Pancreatoduodenectomy
by
Liu, Jingxia
,
Doyle, Majella B.
,
Fields, Ryan C.
in
Anemia
,
Gastroenterology
,
Gastrointestinal surgery
2020
Purpose
Postoperative length of stay (PLOS) and readmission rate are pancreatoduodenectomy (PD) outcome measures, which are reported individually but may be interrelated. The purpose of this study was to evaluate how well a composite length of stay measure (CLOS) that included PLOS and readmission length of stay describes outcomes. To do so, we evaluated how well CLOS correlated to postoperative complications absolutely and compared to PLOS.
Methods
A total of 668 PDs performed between 2011 and 2018 were evaluated. CLOS was calculated from PLOS and readmission length of stay. Complication severity was judged by the Modified Accordion Grading System (MAGS). Multinomial logistical regression models (MLRM) were used to investigate the relationship between either PLOS or CLOS and complications. Multilevel and pairwise area under curves (AUC) using SAS macro %MultAUC were provided for both models.
Results
A total of 432 of 668 patients (65%) developed complications. One hundred seventy-seven patients (27%) were readmitted. Mean PLOS was 10.2 days (7.1 SD) and mean CLOS was 12.3 days (10.1 SD). PLOS and CLOS both were correlated linearly to MAGS grade. Spearman correlation coefficient for CLOS vs. MAGS of 0.68 was higher than that of 0.49 for PLOS vs. MAGS. Multilevel AUC from MLRM using PLOS was 0.66, but multilevel AUC from MLRM using CLOS was 0.71.
Discussion
CLOS provides an accurate estimate of hospital day utilization per patient for PD, reflecting not only the basal hospital recovery time for PD but the added time needed because of readmissions due to complications. It is tightly correlated to number and severity of postoperative complications.
Journal Article
Inability to manage non-severe complications on an outpatient basis increases non-white patient readmission rates after pancreaticoduodenectomy: A large metropolitan tertiary care center experience
by
Doyle, Majella B.
,
Zarate Rodriguez, Jorge G.
,
Fields, Ryan C.
in
Ambulatory Care - statistics & numerical data
,
Blood transfusions
,
Cancer
2021
Pancreaticoduodenectomy (PD) has a high rate of readmission, and racial disparities in care could be an important contributor.
Patients undergoing PD were prospectively followed, and their complications graded using the Modified Accordion Grading System (MAGS). Patient factors and perioperative outcomes for patients with and without postoperative readmission were compared in univariate and multivariate analysis by severity.
837 patients underwent PD, the overall 90-day readmission rate was 27.5%. Non-white race was independently associated with readmission (OR 1.83, p = 0.007). 51.3% of readmissions were for non-severe complications (MAGS <3). Non-white race was independently associated with MAGS non-severe readmission (OR 2.13, p = 0.006), but not MAGS severe readmission.
Non-white patients are more likely to be readmitted, particularly for non-severe complications. Follow up protocols should be tailored to address race disparities in the rates of readmission as readmission for less severe complications could potentially be avoidable.
•Pancreaticoduodenectomy (PD) is a complex procedure with a high readmission rate.•Non-white race is an important risk factor for readmission after PD.•Non-white patients are readmitted disproportionately for non-severe complications.•Follow up protocols should be tailored to address race disparities in readmissions.
Journal Article
Thunderbeat™ Integrated Bipolar and Ultrasonic Forceps in the Whipple Procedure: A Prospective Randomized Trial
by
Liu, Jingxia
,
Hawkins, William G
,
Williams, Gregory A
in
Clinical trials
,
Dissection
,
Fistula
2020
Thunderbeat™ is a device that uses both ultrasonic and advanced bipolar energies to achieve hemostasis. It has been evaluated in a variety of clinical contexts, but no literature exists regarding its application to pancreatic surgery. Using a prospective, randomized controlled trial, we evaluated its safety and efficacy in the Whipple procedure. Thirty-two participants were enrolled in the study. The Thunderbeat™ device during the Whipple procedure showed similar safety profile compared to standard of care.
Journal Article