bluuebunny/crossref_metadata_2025 huggingface dataset:
Donor–Acceptor Copolymers with Rationally Regulated Side Chain Orientation for Polymer Solar Cells Processed by Non-Halogenated Solvent
Authors: Hu Zhengwei , Huang Qiri , Liu Chunchen , Song Ao , Shao Lin , Bai Yuanqing , Hu Zhicheng , Zhang Kai , Huang Fei , Cao Yong
Published: April 2022

A donor–acceptor (D-A) conjugated polymer PBTFO-T-1 consisting of 2,1,3-benzothiadiazole (BT) as A unit and thiophene (T) as D unit was facilely obtained by a straightforward three-step reaction. The BT unit is attached with a fluorine atom and an alkoxy chain to simultaneously endow the polymer with a deep HOMO energy level and desirable solubility. The alkoxyl chain orientation on the BT unit has been regulated and the polymer PBTFO-T-2 with regio-regularly oriented side chains was also developed to investigate the impact of the alkoxyl chain orientation on their optoelectronic properties. The PBTFO-T-1:Y6-BO polymer solar cells (PSCs) were processed with a non-halogenated solvent and achieved an optimized power conversion efficiency of 14.16%, significantly higher than 9.39% of the PBTFO-T-2:Y6-BO counterpart. It has been demonstrated that the PBTFO-T-1:Y6-BO film exhibits higher and more balanced charge transportation and superior film morphology, resulting in higher exciton generation and dissociation, less recombination and eventually the higher short-circuit current density (J
sc) and fill factor. This study provides a possible strategy to develop polymer donors with low cost for future commercial applications of PSCs and gives some insights into regulating optoelectronic properties of polymer donors via rationally modifying their side chain orientation.
Efficacy of aggressive hydration with normal saline versus lactated Ringer’s solution for the prevention of post-ERCP pancreatitis in high-risk patients: a randomized controlled trial
Authors: Patel Rupal , Bertran-Rodriguez Carlos , Kumar Ambuj , Brady Patrick , Gomez-Esquivel Rene , Changela Kinesh , Niknam Negar , Taunk Pushpak
Published: April 2022

Background and study aims Post-ERCP pancreatitis (PEP) is a common adverse event in high-risk patients. Current intervention known to reduce the incidence and severity of PEP include pancreatic duct stent placement, nonsteroidal anti-inflammatory drugs per rectum, and intravenous (IV) fluids. We compared aggressive normal saline (NS) vs aggressive lactated Ringer’s (LR) infusion for the prevention of PEP in high-risk patients undergoing ERCP.

Patients and methods Patients were randomized to receive either an aggressive infusion of NS or LR. The infusion was started at a rate of 3 mL/kg/hr and continued throughout the ERCP procedure. A 20 mL/kg bolus was given at the end of the procedure, then continued at a rate of 3 mL/kg/hr.

Results A total of 136 patients were included in our analysis. The incidence of PEP was 4 % (3/72 patients) in the LR group versus 11 % (7/64 patients) in the NS group resulting in a relative risk (RR) of 0.38 (95 % confidence interval [CI] 0.10 to 1.42; P = 0.19). The relative risk reduction (RRR) was 0.62 (95 % CI –0.41 to 0.90) along with an absolute risk reduction (ARR) of 0.07 (95 % CI –0.025 to 0.17) and an number needed to treat of 15 (95 % CI –41 to 6).

Conclusions To our knowledge, this is the first study comparing aggressive IV NS to aggressive IV LR in high-risk patients. The incidence of PEP was lower in the group receiving an aggressive LR infusion (4 %) compared to NS infusion (11 %). However, the difference was not statistically significant likely due to poor accrual thereby impacting the power of the study.
Role of Serum Carcinoembryonic Antigen in Predicting Recurrent Disease following Curative Resection of Rectal Cancer
Authors: Soma Srikanth , Gurnule Sachin
Published: April 2022

Introduction Surveillance of patients following definitive treatment of rectal malignancy is based on the predicament that early detection of recurrence may provide an opportunity for cure. Available methods for monitoring include clinical, radiological, and serum tests. The purpose of this study was to determine the effectiveness of CEA in detecting recurrences.

Materials and Methods Retrospective analysis of patients with adenocarcinoma rectum treated with curative intent between 2012 to 2020 at our institute was performed. Postoperatively, patients were followed with CEA measurements according to our institution protocol and elevation of serum CEA above 5 ng/dL was considered as suspicious of recurrence.

Results One hundred ninety patients who received curative treatment were deemed eligible for the analysis. Among these 61 patients had recurrences during the follow-up period and postoperative CEA measurements at the time of recurrence were analyzed in all the patients. Sensitivity, specificity, positive predictive value, and negative predictive value of postoperative CEA to detect recurrences are 81.9, 92.2, 83.3, and 91.5%, respectively.

Conclusion CEA surveillance following definitive management of rectal cancer detects recurrences in majority of the patients and hence strongly recommended.
To Anticoagulate or Not to Anticoagulate in COVID-19: Lessons after 2 Years
Authors: Rizk John G. , Gupta Aashish , Lazo Jose G. , Sardar Partha , Henry Brandon Michael , Lavie Carl J. , Effron Mark B.
Published: April 2022

A hypercoagulable state associated with coronavirus disease 2019 (COVID-19) has been well documented and is believed to be strongly supported by a proinflammatory state. The hypercoagulable state in turn results in increased incidence of arterial and venous thromboembolism (VTE) seen in hospitalized COVID-19 when compared with hospitalized non-COVID-19 patient cohorts. Moreover, patients with arterial or VTE and COVID-19 have higher mortality compared with COVID-19 patients without arterial or VTE. Prevention of arterial or VTE thus remains an essential question in the management of COVID-19 patients, especially because of high rates of reported microvascular and macrovascular thrombosis. This has prompted multiple randomized control trials (RCTs) evaluating different anticoagulation strategies in COVID-19 patients at various stages of the disease. Herein, we review findings from RCTs in the past 2 years of antithrombotic therapy in critically ill hospitalized patients, noncritically ill hospitalized patients, patients postdischarge from the hospital, and outpatients. RCTs in critically ill patients demonstrated therapeutic dose anticoagulation does not improve outcomes and has more bleeding than prophylaxis dose anticoagulant in these patients. Trials in noncritically ill hospitalized patients showed a therapeutic dose anticoagulation with a heparin formulation might improve clinical outcomes. Anticoagulation with a direct oral anticoagulant posthospital discharge may improve outcomes, although there is a large RCT in progress. Nonhospitalized COVID-19 patients have an insufficient burden of events to be candidates for antithrombotic therapy. Anticoagulation in pregnant and lactating patients with COVID-19, as well as antiplatelet therapy for COVID-19, is also reviewed.
Integrate the integrators! A call for establishing academic careers for integration experts
Authors: Hoffmann Sabine , Deutsch Lisa , Klein Julie Thompson , O’Rourke Michael
Published: April 2022

Integration is often considered the core challenge and the defining characteristic of inter- and trans-disciplinary (ITD) research. Given its importance, it is surprising that the current system of higher education does not provide permanent positions for integration experts; i.e., experts who lead, administer, manage, monitor, assess, accompany, and/or advise others on integration within ITD projects or programs. Based on empirical results of an ITD 2019 Conference Workshop entitled “Is there a new profession of integration experts on the rise?” held in Gothenburg, Sweden, and our own experience in leading and studying ITD integration, the present article sheds light on the overarching question, “What are integration experts?”, thus contributing to the emerging literature on integration and integration expertise. We use direct quotes from participants to substantiate workshop results and triangulate them with recent literature on ITD research as well as Science of Team Science (SciTS) and Science and Technology Studies (STS). We conclude our article by discussing possible unintended consequences of establishing academic careers for integration experts, and suggest four complementary ways to support them, while mitigating potentially negative consequences: (a) establishing an international Community of Practice (CoP) to foster peer-to-peer exchange among integration experts, create greater visibility, and develop ideas for transforming academic structures; (b) studying academic careers of integration experts to provide empirical evidence of “successful” examples and disclose different ways of establishing related academic positions; (c) funding respective positions and aligning metrics for ITD research to foster integration within ITD projects or programs; and (d) engaging in collaborative dialog with academic institutions and funding agencies to present empirical results and lessons learnt from (a) and (b) to support them in establishing and legitimating careers for integration experts. If academia is to be serious about addressing the most pressing environmental and societal problems of our time, it needs to integrate its integrators.
Capillary model tracks blood flow in healthy and diseased networks
Authors: Thompson Avery
Published: April 2022

3D model of retina capillary networks provides insight on flow of blood cells, impacts of constricted vessels
The anisotropic fatigue properties of extruded Al–Zn–Mg–Cu alloy
Authors: Peng Yiwen , Zhao Junwen , Wang Chaoqun , Han Ruipeng , Liu Yifeng
Published: April 2022

The effect of specimen orientation on the fatigue properties of extruded Al–Zn–Mg–Cu alloy was investigated, and the relationship between tensile properties and fatigue strength was established. The results show that the fatigue properties of specimens vary largely with the orientation. The specimens with 0° orientation (relative to extrusion direction) have the highest fatigue strength, i.e. 301.3 MPa, whereas the fatigue strength of specimens with 45°and 90° orientation was reduced by 13.3% and 33.5%, respectively. The fatigue strength is linearly proportional to the elongation. It was found that the crack propagation modes vary with specimen orientation, a result of the grain orientation and intergranular coarse second phase particles, leading to the difference in fatigue lives. In addition, Basquin equations for specimens in the three directions were proposed for fatigue life prediction.
Influence of Ti3C2Tx addition on the corrosion behaviour and tribological properties of electrodeposited Ni-W-Ti3C2Tx nanocomposite coatings
Authors: Xiao Qi , Zou Jinming , Chen Baoquan , Luo Jiaxin , Lu Yaojun , Chen Weiqing , Zhang Xuehui , Liang Tongxiang
Published: April 2022

Present study deals with the comparative wear and corrosion behaviour of electrodeposited Ni-W-Ti3C2Tx composite coatings. The composite coatings were prepared by direct current electrodeposition method in bath with different amounts of Ti3C2Tx. Reciprocating friction was used to analyse the wear behaviour of the coating. The corrosion resistance of all coatings was examined by potential polarisation and electrochemical impedance spectroscopy. The results show that the wear rate and friction coefficient are the lowest for Ni-W-20Ti3C2Tx composite coating among all the coatings, which is attributed to the lubrication effect of Ti3C2Tx. Moreover, the Ti3C2Tx can effectively improve the corrosion resistance of Ni-W alloy coating, and the optimum addition of 20 mg/L is reached, which is determined by Ni (111) texture and surface quality.
Effects of graphene on the mechanical properties of AlSi10Mg melted by SLM
Authors: Qiu Jiaqing , Chen Changjun , Zhang Min
Published: April 2022

Graphene(GNPs) aluminum matrix composites have been widely used in transportation, aerospace, energy and power fields due to their high strength, good wear resistance and small thermal expansion coefficient. In this paper, AlSi10Mg-(0,0.5,1.0,2.0,4.0wt.%)graphene composite powders were prepared by vacuum mechanical milling, and then high quality composites were fabricated by selective laser melting(SLM). The SLM process of the composites was optimized, the microstructure and mechanical properties of AlSi10Mg-(0,0.5,1.0,2.0,4.0wt.%) graphene composites were analyzed. The results of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy(EDS) and X-ray diffraction(XRD) showed, with the addition of graphene, the microstructure and mechanical properties of the samples are greatly affected. This benign change in the microscopic level has brought the improvement of mechanical properties to the sample.
Evaluating Nebraska’s local comprehensive plans to achieve the national wetland conservation missions in the USA
Authors: Zhang Ligang , Hu Qiao , Hayes Michael , Burbach Mark , Messer Tiffany , Zhou Yuzhen , Tang Zhenghong
Published: April 2022

The U.S. federal government’s requirements and guidance for wetland conservation are reflected in a series of federal laws, regulations, and policies. However, the degree to which these requirements are reflected in local planning efforts is unclear. This study using five components with 56 indicators evaluates how well wetland conservation efforts are integrated into 112 local comprehensive plans in Nebraska, USA. The results show that the majority of local comprehensive plans pay little direct attention to wetland conservation, although many conservation efforts are conducted under the umbrella of environmental protection frameworks. The indicators include water resource protection received the highest score and was the descriptor of natural or environmental resources and resulted in the highest level of local awareness on natural assets. The indicator of setting goals for no net loss of wetlands received the lowest score among all indicators, demonstrating a clear gap between the national vision and the local reality of wetland conservation. Findings suggest local governments need more direct and proactive inputs to improve wetland conservation. Further findings from this research provide a practical roadmap for planners globally, particularly for the developing countries, to integrate wetland conservation into the local planning systems.
Passivation efficacy study of Al2O3 dielectric on self-catalyzed molecular beam epitaxially grown GaAs1-x
Sb
x
nanowires
Authors: Parakh Mehul , Ramaswamy Priyanka , Devkota Shisir , Kuchoor Hirandeep , Dawkins Kendall , Iyer Shanthi
Published: April 2022

This work evaluates the passivation efficacy of thermal atomic layer deposited (ALD) Al2O3 dielectric layer on self-catalyzed GaAs1-x
Sb
x
nanowires (NWs) grown using molecular beam epitaxy. A detailed assessment of surface chemical composition and optical properties of Al2O3 passivated NWs with and without prior sulfur treatment were studied and compared to as-grown samples using x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and low-temperature photoluminescence (PL) spectroscopy. The XPS measurements reveal that prior sulfur treatment followed by Al2O3 ALD deposition abates III–V native oxides from the NW surface. However, the degradation in 4K-PL intensity by an order of magnitude observed for NWs with Al2O3 shell layer compared to the as-grown NWs, irrespective of prior sulfur treatment, suggests the formation of defect states at the NW/dielectric interface contributing to non-radiative recombination centers. This is corroborated by the Raman spectral broadening of LO and TO Raman modes, increased background scattering, and redshift observed for Al2O3 deposited NWs relative to the as-grown. Thus, our work seems to indicate the unsuitability of ALD deposited Al2O3 as a passivation layer for GaAsSb NWs.
Two-dimensional attractors of A-flows and fibred links on three-manifolds
Authors: Medvedev V , Zhuzhoma E
Published: April 2022

Let f

t
be a flow satisfying Smale’s Axiom A (in short, A-flow) on a closed orientable three-manifold M
3, and Ω a two-dimensional basic set of f

t
. First, we prove that Ω is either an expanding attractor or contracting repeller. Next, one considers an A-flow f

t
with a two-dimensional non-mixing attractor Λ
a
. We construct a casing M(Λ
a
) of Λ
a
that is a special compactification of the basin of Λ
a
by a collection of circles L(Λ
a
) = {l
1, …, l

k
} such that M(Λ
a
) is a closed three-manifold and L(Λ
a
) is a fibre link in M(Λ
a
). In addition, f

t
is extended on M(Λ
a
) to a nonsingular structurally stable flow with the non-wandering set consisting of the attractor Λ
a
and the repelling periodic trajectories l
1, …, l

k
. We show that if a closed orientable three-manifold M
3 has a fibred link L = {l
1, …, l

k
} then M
3 admits an A-flow f

t
with the non-wandering set containing a two-dimensional non-mixing attractor and the repelling isolated periodic trajectories l
1, …, l

k
. This allows us to prove that any closed orientable n-manifold, n ⩾ 3, admits an A-flow with a two-dimensional attractor. We prove that the pair

M

(

Λ

a

)

;
L

(

Λ

a

)

consisting of the casing M(Λ
a
) and the corresponding fibre link L(Λ
a
) is an invariant of conjugacy of the restriction

f

t

|

W

s

(

Λ

a

)

of the flow f

t
on the basin of the attractor Λ
a
.
Exponential stability estimate for the derivative nonlinear Schrödinger equation*
Authors: Cong Hongzi , Mi Lufang , Wu Xiaoqing , Zhang Qidi
Published: April 2022

In this paper, we prove an exponential long time stability result for the derivative nonlinear Schödinger equation (DNLS) in some Sobolev space by using Birkhoff normal form technique and some suitable nonresonant conditions.
Geometric estimates for doubly nonlinear parabolic PDEs
Authors: Bezerra Júnior Elzon C , da Silva João Vitor , Ricarte Gleydson C
Published: April 2022

In this manuscript, we establish

C

loc

α
,

α

θ

regularity estimates for bounded weak solutions of a certain class of doubly degenerate evolution PDEs, whose simplest model case is given by

∂
u

∂
t

−
d
i
v

(

m
|
u

|

m
−
1

|
∇
u

|

p
−
2

∇
u

)

=
f

(

x
,
t

)

in

Ω

T

≔
Ω
×

(

0
,
T

)

,

where m ⩾ 1, p ⩾ 2 and f belongs to a suitable anisotropic Lebesgue space. Employing intrinsic scaling techniques and geometric tangential methods, we derive sharp regularity estimates for such models, which depend only on universal and compatibility parameters of the problem. In this scenario, our results are natural improvements for former ones in the context of nonlinear evolution PDEs with degenerate structure via a unified approach. As a consequence of our findings and approach, we address a Liouville type result for entire weak solutions of a related homogeneous problem with frozen coefficients and asymptotic estimates under a certain approximating regime, which may have their own mathematical interest. We also present examples of degenerate PDEs where our results can be applied.
Single-photon blockade in quasichiral atom–photon interaction: simultaneous high purity and high efficiency
Authors: Lu Yu-Wei , Liu Jing-Feng , Li Runhua , Wu Yanxiong , Tan Haishu , Li Yongyao
Published: April 2022

We investigate the single-photon blockade (1PB) in the quasichiral regime of atom–photon interaction, where the effective coupling between the cavity and the atom is bidirectional but asymmetrical, achieved by coupling to a dissipative environment. A synthetic magnetic current ϕ is induced in the closed-loop coupling, which breaks down the reciprocity of atom–photon interaction, and can be utilized to create asymmetrical or even unidirectional effective coupling between two selected quantum states. As an example, we couple the single-atom cavity quantum electrodynamics (QED) system to a strongly dissipative plasmonic cavity. We find that in the quasichiral regime, the unconventional photon blockade (UPB) and the conventional photon blockade (CPB) realize simultaneously in the condition of maximum chirality (ϕ = π/2 and 3π/2). As a result, 1PB in the quasichiral regime can combine the advantages of both UPB and CPB, demonstrating the perfect single-photon purity, higher efficiency, non-oscillating time dynamics as well as lower requirement of mode coupling to achieve UPB. Our work paves the way for 1PB towards practical applications and reveals the intriguing quantum-optics phenomena in the quasichiral light–matter interaction.
Start of experiments in the design configuration of the GOL-NB multiple-mirror trap
Authors: Postupaev V.V. , Batkin V.I. , Burdakov A.V. , Burmasov V.S. , Ivanov I.A. , Kuklin K.N. , Lykova Yu.A. , Melnikov N.A. , Mekler K.I. , Nikishin A.V. , Polosatkin S.V. , Rovenskikh A.F. , Sidorov E.N. , Skovorodin D.I.
Published: April 2022

A multiple-mirror confinement is an alternative concept in fusion energy development that improves the particle and energy confinement times in open traps (linear magnetic systems). The paper discusses the development progress of the GOL-NB multiple-mirror experiment that was recently commissioned at BINP. The reference description of the GOL-NB hardware is presented. Properties of a low-temperature start plasma are discussed. The first results from test experiments with injection of one 25 keV neutral beam are shown. Methods of plasma stabilization in the non-min-B configuration are discussed. In general, the ongoing commissioning progress and results of the preliminary experiments are modestly optimistic for the expected device performance.
Thermostability and catechol-O-methyltransferase inhibitory activity of acylated anthocyanins from purple yam
Authors: Miyata Ryo , Sano Hitomi , Hoshino Sara , Kumazawa Shigenori
Published: April 2022

The thermostability of purple yam was investigated to be used as natural colorants. In addition, the inhibitory properties of purple yam and its isolated anthocyanins toward human catechol-O-methyltransferase (COMT), a key neurotransmitter involved in Parkinson's disease and depression, were also investigated. The thermostability of purple yam was higher than that of the reference samples (purple sweet potato and purple potato). Quantitative HPLC analysis revealed that alatanin A (2) contributed to the thermostability of purple yam. Methanol extracts of purple yam exhibited the highest COMT inhibitory activity of the tested samples. Alatanin D (1) showed the highest inhibitory activity of the anthocyanins in purple yam (IC50 19 µM). This study revealed the thermostability and COMT inhibitory activity of purple yam and may lead to its use not only as a thermostable natural source of colorants, but also for the prevention and treatment of Parkinson's disease and depression.
Circadian rhythmicity of pain sensitivity in humans
Authors: Daguet Inès , Raverot Véronique , Bouhassira Didier , Gronfier Claude
Published: April 2022

Pain intensity has been reported to fluctuate during the day in some experimental and clinical conditions, but the mechanisms underlying these fluctuations are unknown. Although the circadian timing system is known to regulate a wide range of physiological functions, its implication in pain regulation is largely unknown.

Using highly controlled laboratory constant-routine conditions, we show that pain sensitivity is rhythmic over the 24 h and strongly controlled by the endogenous circadian timing system. We found that the circadian component of pain sensitivity can be modelled with a sinusoidal function, with a maximum in the middle of the night and a minimum in the afternoon. We also found a weak homeostatic control of pain sensitivity, with a linear increase over the 34 h of prolonged wakefulness, which slowly builds up with sleep pressure. Using mathematical modelling, we describe that the circadian system accounts for ∼80% of the full magnitude of pain sensitivity over the 24 h, and that sleep-related processes account for only ∼20%.

Overall, our data reveal the neurobiological mechanisms involved in driving the rhythmicity of pain perception in humans. We show that pain sensitivity is controlled by two superimposed processes: a strong circadian component and a modest homeostatic sleep-related component. Our findings highlight the need to consider time of day in pain assessment, and indicate that personalized circadian medicine may be a promising approach to pain management.
Reframing postconcussional syndrome as an interface disorder of neurology, psychiatry and psychology
Authors: Clark Camilla N , Edwards Mark J , Ong Bee Eng , Goodliffe Luke , Ahmad Hena , Dilley Michael D , Betteridge Shai , Griffin Colette , Jenkins Peter O
Published: April 2022

Persistent symptoms following a minor head injury can cause significant morbidity, yet the underlying mechanisms for this are poorly understood. The shortcomings of the current terminology that refer to non-specific symptom clusters is discussed. This update considers the need for a multi-dimensional approach for the heterogenous mechanisms driving persistent symptoms after mild traumatic brain injury. Relevant pathophysiology is discussed to make the case for mild traumatic brain injury to be conceptualized as an interface disorder spanning neurology, psychiatry and psychology. The relevance of pre-injury factors, psychological co-morbidities and their interaction with the injury to produce persistent symptoms are reviewed. The interplay with psychiatric diagnoses, functional and somatic symptom disorder presentations and the influence of the medicolegal process is considered. The judicious use and interpretation of investigations given the above complexity is discussed, with suggestions of how the explanation of the diagnostic formulation to the patient can be tailored, including insight into the above processes, to aid recovery. Moving beyond the one-dimensional concept of ‘postconcussional syndrome’ and reframing the cause of persistent symptoms following mild traumatic brain injury in a bio-psycho-socio-ecological model will hopefully improve understanding of the underlying contributory mechanistic interactions and facilitate treatment.
6: PALLIATIVE GASTRECTOMY FOR METASTATIC GASTRIC ADENOCARCINOMA: A NATIONAL POPULATION-BASED COHORT STUDY
Authors: Kamarajah S , Markar S , Phillips A , Salti G , Dahdaleh F , Griffiths E
Published: April 2022

Background and aim

The impact of palliative gastrectomy for metastatic gastric adenocarcinoma, especially by site of metastasis remains unclear. This study aimed to evaluate the long-term outcomes of palliative gastrectomy for metastatic gastric adenocarcinoma.

Methods

The National Cancer Database (2010–2015) was used to identify patients with clinical metastatic (cM1) gastric adenocarcinoma (n = 19,411) at diagnosis. The main variable was index management for cM1 gastric adenocarcinoma (i.e. no treatment, palliative chemotherapy or palliative gastrectomy). Cox multivariable analyses were used to account for treatment selection bias.

Results

Of 19,411 patients, 10,893 (56%) received palliative chemotherapy, and only 1,101 (6%) received palliative gastrectomy only. The median survival was 6.1 months, and 5-year survival was 4% in the entire cohort. Patients receiving palliative gastrectomy had a significantly longer survival than patients without any treatment or palliative chemotherapy (median: 12.8 vs 1.8 vs 9.5 months, P < 0.001), which remained after multivariable adjustment (HR: 0.30, CI95%: 0.28–0.33, P < 0.001). Stratified analyses by clinical nodal stage (cN) demonstrated survival benefit with palliative gastrectomy: cN0 (HR: 0.28, CI 95%: 0.24–0.32), cN1 (HR: 0.27, CI 95%: 0.23–0.31), cN2 (HR: 0.29, CI 95%: 0.24–0.37), and cN3 (HR: 0.26, CI 95%: 0.20–0.32). Palliative gastrectomy remained superior compared to palliative chemotherapy for metastatic disease limited to liver, bone and peritoneum, but equivalent to lung metastasis and inferior to brain metastasis.

Conclusion

Palliative gastrectomy appears to have a modest survival benefit over palliative chemotherapy alone. Differences in outcomes by site of metastasis warrant further research to understand tumor biology and identify specific subgroups which may benefit from palliative gastrectomy.
8: ARE ELDERLY PATIENTS AT INCREASED PERIOPERATIVE MORBIDITY AND MORTALITY FROM OESOPHAGECTOMY FOR OESOPHAGEAL CANCER? A SYSTEMATIC MAPPING REVIEW AND META-ANALYSIS
Authors: Gujjuri R , Kamarajah S , Elhadi M , Umar H , Subramanya M , Evans R , Griffiths E
Published: April 2022

Background and aim

Oesophagectomy is being increasingly performed in an ageing population that is observing a concomitant growth in the life expectancy. However, the risks are poorly quantified, and this study aims to review current evidence to further quantify the postoperative of oesophagectomy in the elderly population compared to younger patients.

Methods

A systematic electronic search was conducted for studies reporting oesophagectomy in the elderly population. Meta-analysis was performed using random-effects modelling to compute odds ratios (OR) and 95% confidence intervals (CI). Primary outcome was overall complications and secondary outcomes included anastomotic leaks, cardiac complications, pulmonary complications, overall and disease-free survival. Meta-regression was performed to identify study-, hospital- and patient-level factors confounding study findings.

Results

This review included 37 eligible studies involving 61,723 patients. Increasing age was significantly associated with increased rates of overall complications (OR: 1.67, CI95%: 1.42–1.97), cardiac complications (OR: 1.62, CI95%: 1.10–2.40), pulmonary complications (OR: 1.44, CI95%: 1.11–1.87) and decreased 5-year overall survival (OR: 1.36, CI95%: 1.11–1.66) and 5-year disease-free survival (OR: 1.66, CI95%: 1.40–1.97). Rates of anastomotic leaks showed no difference between elderly and younger patients (OR: 1.06, CI95%: 0.71–1.59).

Conclusion

Postoperative outcomes such as overall complications, 5-year overall survival and disease-free survival appear to significantly worse in all age cut-offs in this meta-analysis. Sarcopenia and frailty act as better predictors of postoperative outcomes than chronological age. This study confirms the preconceived suspicions of increased risks in elderly patients following oesophagectomy and will aid future pre-operative counselling and informed consent.
10: INTRATHORACIC VERSUS CERVICAL ANASTOMOSIS AFTER MINIMALLY INVASIVE OESOPHAGECTOMY FOR OESOPHAGEAL CANCER: A RANDOMISED CONTROLLED TRIAL
Authors: Van Workum F , Verstegen M , Klarenbeek B , Bouwense S , Van Berge Henegouwen M , Daams F , Gisbertz S , Hannink G , Haveman J W , Heisterkamp J , Jansen W , Kouwenhoven E , Van Lanschot J , Nieuwenhuijzen G , Van Der Peet D , Polat F , Ubels S , Wijnhoven B , Rovers M , Rosman C
Published: April 2022

Background and aim

Transthoracic minimally invasive oesophagectomy (MIO) is increasingly performed as part of curative multimodality treatment. There is no robust evidence on the preferred location of the anastomosis after transthoracic MIO. The aim of this study was to compare an intrathoracic with a cervical anastomosis in a randomised controlled trial.

Methods

An open multicentre randomised controlled superiority trial was performed. Patients with mid to distal oesophageal or gastro-oesophageal junction cancer planned for curative resection were included. Patients were randomly assigned (1:1) to transthoracic MIO with intrathoracic or cervical anastomosis. The primary endpoint was anastomotic leakage requiring endoscopic, radiologic or surgical intervention. Secondary outcomes were overall anastomotic leak rate, other postoperative complications, length of stay, mortality and quality of life. The ICAN trial is registered in the Dutch trial register under number NTR4333.

Results

Two hundred and sixty-two patients were randomised and 245 were eligible for analysis. Anastomotic leakage necessitating re-intervention occurred in 15 of 122 (12.3%) patients with intrathoracic anastomosis and in 39 of 123 (31.7%) patients with cervical anastomosis (risk difference − 19.4%, 95% CI -29.5%—-9.3%). Overall anastomotic leak rate was 12.3% in the intrathoracic anastomosis group and 34.1% in the cervical anastomosis group (risk difference − 21.9%, 95% CI -32.1%—-11.6%). ICU length of stay, mortality rates and overall quality of life were comparable between groups, but intrathoracic anastomosis was associated with less severe complications, lower incidence of recurrent laryngeal nerve palsy and better quality of life in three subdomains.

Conclusion

Intrathoracic anastomosis is the preferred technique for patients treated with transthoracic MIO for mid to distal oesophageal or gastro-oesophageal junction cancer.
19: CARDIOPULMONARY FUNCTION FOLLOWING NEO-ADJUVANT CHEMOTHERAPY FOR OESOPHAGO-GASTRIC ADENOCARCINOMA
Authors: Penney N , Dirie J , Jeffreys N , Siddig A , Currie A , Kamocka A , Prabhu P , Abbassi-Ghadi N , Singh P , Preston S R
Published: April 2022

Background and aim

The role of perioperative chemotherapy in oesophago-gastric adenocarcinoma is well established. Epirubicin, Cisplatin/Oxaliplatin and Capecitabine (ECX/EOX) based regimens have recently been challenged by Fluoruracil, Leucovorin, Oxaliplatin and Docetaxel (FLOT). We aimed to assess whether these regimens had variable effects on patient cardiopulmonary fitness and subsequent suitability for major surgery following treatment.

Methods

Cardiopulmonary exercise (CPEX) testing was used to provide objective estimation of cardiopulmonary function metrics including peak oxygen consumption (VO₂ max), anaerobic threshold (AT) and ventilatory efficiency (VeVCO₂ slope). Paired CPEX testing was performed in participants undergoing treatment for oesophago-gastric adenocarcinoma pre and post FLOT (n = 26) or ECX/EOX (n = 51) chemotherapy regimens, as selected by the multidisciplinary team. Univariate non-parametric testing was used to assess differences for significance.

Results

Participants undergoing FLOT were younger [median (IQR): 61(12.5) □□. 69(11) years, P = 0.003] and had a higher pre-chemotherapy VO₂ max/m2 [929(231) □□. 838(198) ml/m2/min, P = 0.040] and FEV1 [3.5(0.8) □□. 2.9(0.6), P = 0.017] compared to those undergoing ECX/EOX. Other metrics including BMI, weight, VO₂ max/kg, AT, VeVCO₂ slope, FVC and FEV1 were not significantly different at baseline. There was no difference in time to CPEX testing after completing chemotherapy treatment [median 27 □□. 27 days]. Both FLOT and ECX/EOX significantly reduced VO₂ max/kg [−2.85(4.0) & -1.70(3.5) ml/kg/min], VO₂ max/m2 [−101(193) & -68(155) ml/m2/min] and AT [−1.35(2.7) & -1.1(2.3) ml/kg/min] respectively (all P < 0.001), with no significant absolute or proportional differences found between the groups. Respiratory function was not altered.

Conclusion

A reduction in cardiopulmonary function should be accounted for when planning surgery for oesophago-gastric cancer following neo-adjuvant chemotherapy. We did not find significant differences in cardiopulmonary function reduction between chemotherapy regimens in this cohort. However, there was a trend towards a greater reduction in cardiopulmonary function after FLOT and studies in larger cohorts of patients are needed to clarify this.
30: STRONG IMPACT OF SARCOPENIA AS A RISK FACTOR OF SURVIVAL IN RESECTED GASTRIC CANCER PATIENTS: FIRST REPORT FROM AN ITALIAN CANCER CENTER
Authors: Ricciardolo A A , De Ruvo N , Prampolini F , Pecchi A , Missori G , Sorrentino L , Rossi E G , Fenocchi S , Salati M , Spallanzani A , Cautero N , Serra F , Gelmini R
Published: April 2022

Background and aim

Gastric cancer (GC) accounts for 4% of all cancers in Europe. Sarcopenia is a complex syndrome characterized by a loss of muscle mass and function associated with age, often present in neoplastic diseases. Recently several studies have shown a significant association between sarcopenia and poor prognosis in various pathological conditions.

Methods

This observational retrospective study investigates the association between sarcopenia and outcome, both as RFS and OS, in patients with GC undergoing surgery with curative intent. For 50 patients, 25 male and 25 female, the preoperative CT calculation of the skeletal muscle index (SMI) at L3-level allowed us to identify 34 patients with and 16 without sarcopenia. Kaplan-Meyer and univariable and multivariable Cox regression analysis were performed to determine difference in survival and presence of independent prognostic factors.

Results

A statistically significant difference between the sarcopenic and non-sarcopenic groups was observed in both overall survival (OS) and recurrence-free survival (RFS) (P < 0.023; P < 0.006). Moreover, sarcopenia was strongly correlated to a higher risk of recurrence in univariate and multivariate analysis (P < 0.02).

Conclusion

Sarcopenia can be considered a critical risk factor for survival in patients with resectable GC.
31: UTILITY OF ABDOMINAL DRAIN IN GASTRECTOMY (ADIGE) TRIAL: STUDY PROTOCOL FOR A MULTICENTER NON-INFERIORITY RANDOMIZED TRIAL
Authors: Weindelmayer J , Mengardo V , Veltri A , Baiocchi G L , Giacopuzzi S , Verlato G , De Manzoni G
Published: April 2022

Background and aim

Prophylactic use of abdominal drain in gastrectomy has been questioned in the last 15 years and a 2015 Cochrane meta-analysis on four RCTs concluded that there was no convincing evidence to the routine drain placement in gastrectomy. Nevertheless, the Authors evidenced the moderate/low quality of the included studies and highlighted how 3 out of 4 came from Eastern countries. After 2015 only retrospective studies have been published, all with inconsistent results.

Methods

ADiGe (Abdominal Drin in GastrEctomy) Trial is a multicenter prospective randomized non-inferiority trial with a parallel design. It aimed to verify whether avoiding routine use of abdominal drain is burdened with complications, particularly an increase in postoperative invasive procedures. Patients with gastric cancer, scheduled for subtotal or total gastrectomy with curative intent, are eligible for inclusion, irrespective of previous oncological treatment. The primary composite endpoint is reoperation or percutaneous drainage procedures within 30 postoperative days. The primary analysis will verify whether the incidence of the primary composite endpoint is higher in the experimental arm, avoiding routine drain placement, than control arm, undergoing prophylactic drain placement, in order to falsify or support the null hypothesis of inferiority. Secondary endpoints assessed for superiority are overall morbidity and mortality, Comprehensive Complications Index, incidence and time for diagnosis of anastomotic and duodenal leaks, length of hospital stay, readmission rate.

Trial registration

Prospectively registered (last updated on October 29, 2020) at Clinicaltrials.gov with the identifier NCT04227951, https://clinicaltrials.gov/ct2/show/NCT04227951.

Results

Assuming one-sided alpha of 5%, and cumulative incidence of the primary composite endpoint of 6.4% in control arm and 4.2% in the experimental one, 364 patients allow to achieve 80% power to detect a non-inferiority margin difference between the arm proportions of 3.6%. Considering a 10% drop-out rate, 404 patients are needed. In order to have a balanced percentage between total and subtotal gastrectomy, recruitment will end at 202 patients for each type of gastrectomy. The surgeon and the patient are blinded until the end of the operation, while postoperative course is not blinded to patient and caregivers.

Conclusion

ADiGe Trial could contribute to critically re-evaluate the role of prophylactic drain in gastrectomy, a still widely used procedure.
43: NEOADJUVANT CHEMOTHERAPY OFFERS NO SURVIVAL BENEFIT FOR CT2N0M0 GASTRIC ADENOCARCINOMA. A MULTICENTRIC EUROPEAN STUDY
Authors: Abboretti F , Lambert C , Schäfer M , Le Roy B , Mège D , Demartines N , Pezet D , Gronnier C , Mantziari S
Published: April 2022

Background and aim

According to current international guidelines, the optimal treatment of stage cT2N0M0 gastric adenocarcinoma consists of preoperative chemotherapy followed by surgery. Surgery first may be suggested in selected patients, especially if considered unfit for chemotherapy. The aim of the present study was to assess if cT2N0M0 patients treated with surgery first (S) had inferior overall and disease-free survival compared to those treated with neoadjuvant chemotherapy followed by surgery (CS).

Methods

A retrospective analysis was performed among 32 centers, including all consecutive patients with gastric adenocarcinoma operated between January 2007 and December 2017. Patients with cT2N0M0 stage were divided into two groups, surgery first (S) and neoadjuvant chemotherapy followed by surgery (CS). Clinico-pathological details, overall and disease-free survival were compared between the groups. Cox regression analysis was performed for long-term survival.

Results

Among the 2131 included patients, 202 (9.5%) had cT2N0M0 disease: 68 (33.7%) were placed in the CS group and 134 (66.3%) in the S group. CS patients were younger (mean age 62.7 ± 12.8 vs 69.8 ± 12.1 years, P < 0.001) with WHO status 0 in 60.3% versus 34.5% in S patients (P = 0.006). The CS group had more proximal tumors, undergoing more frequently total gastrectomy (70.6% CS vs 45.5% S, P = 0.001). The median number of resected lymph nodes was similar (22 vs 20.5, P = 0.74). R0 resection margins were obtained in 97.1% CS vs 95.5% S patients (P = 0.72). Adjuvant chemotherapy was more often administered in CS patients (75.8% versus 29.8% in S, P < 0.001). Recurrence occured in 30.9% in CS and 18.1% in S (P = 0.04), predominantly as distant metastases (81% CS vs 75% S, P = 0.76). Overall 5-year survival was similar between CS (74.4%, 95%CI 58.1–85.1) and S groups (66.7%, 95%CI 54.4–76.5, P = 0.73), as was 5-year disease-free survival (DFS) (64.6%, 95%CI 48.4–76.9 for CS vs 62.8%, 95%CI 50.7–72.6 for S, P = 0.82). Perioperative chemotherapy was not associated with OS or DFS in multivariate analysis.

Conclusion

Patients with cT2N0M0 gastric adenocarcinoma did not present a survival or recurrence benefit if treated with CS compared to S. In accordance with esophageal cT2N0 tumors, surgery first might be a valid treatment option for these patients.
48: LAPAROSCOPIC HELLER DOR IS AN EFFECTIVE TREATMENT FOR ESOPHAGEAL-GASTRIC JUNCTION OUTFLOW OBSTRUCTION
Authors: Provenzano L , Salvador R , Nezi G , Capovilla G , Nicoletti L , Pierobon E S , Moletta L , Valmasoni M , Merigliano S , Costantini M
Published: April 2022

Background and aim

Esophago-gastric junction outflow obstruction (EGJOO) is a relatively new clinical entity revealed by high-resolution manometry (HRM) that can have two different etiologies, i.e. idiopathic or secondary (esophageal strictures, eosinophilic esophagitis, giant hiatal hernia, prior fundoplication or bariatric surgery, malignancy). Treatment of EGJOO currently mirrors that of achalasia, but this is based only on few studies with small case series. The aim of this study was to assess the outcome of laparoscopic Heller-Dor (LHD) in patients with EGJOO, as compared with patients with esophageal achalasia.

Methods

Between 2016–2019, all patients with a diagnosis of idiopathic EGJOO and referred to our Centre for dysphagia or food regurgitation were prospectively collected. Naïve EGJOO patients were first given medical treatment with Ca2+ channel blockers for 6 months. Then patients were ‘restaged’: patients without clinical improvement and/or whose integrated relaxation pressure (IRP) had not decreased were scheduled for LHD. EGJOO patients who had already been treated elsewhere with botox injections, pneumatic dilations or Ca2+ channel blockers were scheduled upfront for LHD. Patients with EGJOO who underwent LHD were compared with patients with radiological stage I achalasia. The achalasia group was further analyzed by subgrouping the patients based on the manometric-pattern. Treatment failure was defined as the persistence or reoccurrence of a Eckardt score > 3 or the need for retreatment.

Results

During the study period, 150 patients were enrolled: 25 EGJOO patients and 125 radiological stage I achalasia (25 pattern I, 74 pattern II, and 26 pattern III). The median follow-up was 24 months (IQR: 34–16). Treatment was successful in 96% of patients in the EGJOO group and in 96% of achalasia patients with pattern I, 98.7% in those with pattern II, and 96.2% of those with pattern III (P = 0.50). Six-month post-operative HRM showed a reduction in the LES resting pressure and IRP for all patients in all 4 groups (P < 0.001).

Conclusion

This is the first comparative study based on prospective data collection to assess the outcome of LHD in patients with EGJOO. LHD emerged as an effective treatment for EGJOO, with an excellent success rate, comparable with the procedure’s efficacy in treating early-stage achalasia.
60: CAN PREHABILITATION PREVENT DEVELOPMENT OF SARCOPENIA DURING NEOADJUVANT CHEMOTHERAPY FOR OESOPHAGOGASTRIC ADENOCARCINOMA?
Authors: Chmelo J , Navidi M , Phillips A W , Greystoke A , Sinclair R C
Published: April 2022

Background and aim

Sarcopenia characterised as a loss of muscle mass and function is prevalent in cancer populations. It is known to occur in patients receiving neoadjuvant treatment and is associated with poorer outcomes. Thus, minimizing sarcopenia may lead to improved patient prognosis. It has been suggested that exercise can reverse and prevent sarcopenia. Little is known as to whether prehabilitation as an intervention to enhance patients’ functional capacity prior to surgery can lead to sarcopenia prevention.

Methods

Patients enrolled into a prospective prehabilitation study (ChemoFit) during neoadjuvant chemotherapy (NAC) for oesophagogastric adenocarcinoma (OGA) had their radiological sarcopenia measured before and after neoadjuvant chemotherapy (NAC). Radiological sarcopenia and lean body mass (LBM) were measured from computed tomography scans at the level of the L3 vertebra. ChemoFit patients were compared with an historical cohort (NO-PREHAB) which did not undergo prehabilitation and which had their radiological sarcopenia evaluated prospectively prior to and after NAC for OGA.

Results

The group characteristics are described in the table. Radiological sarcopenia was present prior to NAC in 17/36 (47%) which increased to 26/36 (72%) after NAC amongst ChemoFit patients. Sarcopenia prior to NAC in the NO-PREHAB cohort was 12/28 (43%) which increased to 16/28 (57%) post NAC. Intergroup difference (P = 0.291). Median (IQR) ∆LBM at two time points was in ChemoFit −2.6 kg (−5.2; −0.6) and in NO-PREHAB -3.1 kg (−4.7; −1.0) (P = 0.730).

Conclusion

Radiological sarcopenia increased in both groups during NAC for OGA. Prehabilitation did not prevent this from happening. Other strategies must be explored in order to mitigate against sarcopenia.