Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Example Input: Abstract: The selection of assessment procedures for the preclinical evaluation of haemosorbents and the relationship between such procedures and the intended application are exemplified by examination of the design and utilization of procedures based on the rat. Procedures are described for haemoperfusion and for membrane plasma separation followed by on-line sorbent treatment of plasma (plasma perfusion). These procedures are suitable for single or repeated use, with the animal in an unrestrained and conscious state. The relevance to the intended application is demonstrated with respect to artificial liver support by the ability of rat extracorporeal circuits to provide information on the relationship between sorbent properties and liver regeneration as determined by the proliferative response following partial hepatectomy.
Example Output: Adsorption

Example Input: Abstract: Fifteen patients with intracavitary cardiac tumors were operated on at the Kobe University Hospital between September 1977 and January 1984. Three of the patients were men and twelve were women. They ranged in age from 9 to 75 years. Their symptoms were chest pain, dyspnea, cough, palpitation and syncope. Definite diagnosis was confirmed by echo- and cineangiocardiography. There were 14 benign tumors consisting of 13 myxomas, one leiomyoma and one malignant myxosarcoma. The left atrium was the most common chamber involved (12 instances), followed by the right atrium (3). Surgery was performed in all cases under cardiopulmonary bypass with moderate hypothermia and cold crystalloid cardioplegia. Tumors were removed en bloc at the base with their attachment to the atrial septum or free wall in all cases. Three patients underwent concomitant mitral annuloplasty or mitral commissurotomy. Two cases with left atrial myxoma died postoperatively: one case associated with mitral annuloplasty died of congestive heart failure due to newly developed chordal rupture two months after surgery, and the other died of congestive heart failure 13 months after the first operation. Re-excision for recurrence of the myxosarcoma in the left atrium was performed in the latter case as a second surgical procedure. The remaining 13 cases with benign tumors are doing well and are without recurrence. From these favorable results, surgical intervention should be recommended prior to the occurrence of heart failure and severe complications such as coronary or peripheral embolism whenever cardiac tumors are detected by non-invasive echocardiography and cineangiocardiography.
Example Output: Adolescence

Example Input: Abstract: We examined the proteins in serum and peritoneal fluid of women with endometriosis (and of healthy controls) for evidence of an autoimmune response that might account for their impaired fertility. No antibodies against endometrial glycoproteins or against "progestin dependent endometrial protein" (PEP) were found in any serum or peritoneal fluid sample. Levels of PEP were not different in serum from women with moderate to severe endometriosis (n = 6), with mild endometriosis (n = 21), or from disease-free cycling controls (n = 19). PEP levels in peritoneal fluid from mild endometriosis and from controls did not differ but were elevated ten times in fluid obtained in the secretory phase from women with moderate to severe disease. This suggests that PEP levels in peritoneal fluid reflect the extent of ectopic endometrial growth. The salient finding was a heretofore undescribed protein (mol wt 70,000) in secretory phase peritoneal fluid samples (18/20) and its absence during the proliferative phase (0/35).
Example Output:
Ascitic Fluid