Task: Schema-Matching (source dataset: assays)

Task: 
Please identify the matching columns between Table A and Table B. For each column in Table A, specify the corresponding column in Table B. If a column in A has no corresponding column in Table B, you can map it to null. Represent each column mapping using a pair of column headers in a list, i.e., [Table A Column, Table B column or null]. Provide the mapping for each column in Table A and return all mappings in a list.

No explanation and return the matching columns in a structured JSON format: {"column_mappings": <a list of column pairs>}.

TableA:
|   assay_id | variant_id   |   src_id | assay_subcellular_fraction   | assay_organism   | cell_id   |   doc_id | description                                                                                                 | assay_type   | assay_test_type   | assay_category   | assay_tax_id   | assay_strain   | assay_tissue   |
|-----------:|:-------------|---------:|:-----------------------------|:-----------------|:----------|---------:|:------------------------------------------------------------------------------------------------------------|:-------------|:------------------|:-----------------|:---------------|:---------------|:---------------|
|          1 |              |        1 |                              |                  |           |    11087 | The compound was tested for the in vitro inhibition of platelet 12-lipoxygenase at a concentration of 30 uM | B            |                   |                  |                |                |                |
|          2 |              |        1 |                              |                  |           |      684 | Compound was evaluated for its ability to mobilize calcium in 1321NI cells                                  | F            |                   |                  |                |                |                |
|          3 |              |        1 |                              |                  |           |    15453 |                                                                                                             | B            |                   |                  |                |                |                |
|          4 |              |        1 |                              | Bos taurus       |           |    17841 | Binding affinity against A2 adenosine receptor in bovine striatal membranes using [3H]CGS-21680             | B            |                   |                  | 9913.0         |                |                |
|          5 |              |        1 |                              | Homo sapiens     | 163.0     |    17430 | In vitro cell cytotoxicity against 143-B cell lines (Human osteosarcoma cell line)                          | F            |                   |                  | 9606.0         |                |                |
|          6 |              |        1 |                              | Homo sapiens     | 163.0     |    17430 | In vitro cell cytotoxicity against 143-B cell lines (Human osteosarcoma cell line)                          | F            |                   |                  | 9606.0         |                |                |
|          7 |              |        1 |                              | Mus musculus     | 163.0     |    13799 | Cytotoxic Activity was evaluated against 143B (TK-) tumor cells                                             | F            |                   |                  | 10090.0        |                |                |
|          8 |              |        1 |                              | Homo sapiens     | 163.0     |    17774 | In vitro cell cytotoxicity was determined against 143B cell line                                            | F            |                   |                  | 9606.0         |                |                |
|          9 |              |        1 |                              | Homo sapiens     | 163.0     |     3801 | Inhibitory activity against tumor osteosarcoma cell line 143B after 72 hr continuous exposure to compound   | F            |                   |                  | 9606.0         |                |                |
|         10 |              |        1 |                              | Homo sapiens     | 163.0     |    17430 | In vitro cell cytotoxicity against 143B-LTK cell lines expressed in HSV-1 TK                                | F            |                   |                  | 9606.0         |                |                |

TableB:
|   assays_ss_d | assays_vrnt_d   |   assays_src_d | assays_ss_sbclllr_frctn   | assays_ss_rgnsm   | assays_cll_d   | assays_ss_cll_tp   |   assays_td | assays_rltnshp_tp   |   assays_cnfdnc_scr | assays_crtd_b   | assays_src_ss_d   | assays_chmbl_d   | assays_b_frmt   | assays_tss_d   |
|--------------:|:----------------|---------------:|:--------------------------|:------------------|:---------------|:-------------------|------------:|:--------------------|--------------------:|:----------------|:------------------|:-----------------|:----------------|:---------------|
|             1 |                 |              1 |                           |                   |                |                    |       12052 | H                   |                   8 | Autocuration    |                   | CHEMBL615117     | BAO_0000019     |                |
|             2 |                 |              1 |                           |                   |                |                    |       22226 | U                   |                   0 | Autocuration    |                   | CHEMBL615118     | BAO_0000219     |                |
|             3 |                 |              1 |                           |                   |                |                    |       22226 | U                   |                   0 | Autocuration    |                   | CHEMBL615119     | BAO_0000019     |                |
|             4 |                 |              1 |                           | Bos taurus        |                |                    |      104729 | H                   |                   4 | Autocuration    |                   | CHEMBL615120     | BAO_0000249     |                |
|             5 |                 |              1 |                           | Homo sapiens      | 163.0          | 143B               |       80001 | N                   |                   1 | Intermediate    |                   | CHEMBL615121     | BAO_0000219     |                |
|             6 |                 |              1 |                           | Homo sapiens      | 163.0          | 143B               |       80001 | N                   |                   1 | Intermediate    |                   | CHEMBL615122     | BAO_0000219     |                |
|             7 |                 |              1 |                           | Mus musculus      | 163.0          | 143B               |       80001 | N                   |                   1 | Intermediate    |                   | CHEMBL615123     | BAO_0000219     |                |
|             8 |                 |              1 |                           | Homo sapiens      | 163.0          | 143B               |       80001 | N                   |                   1 | Expert          |                   | CHEMBL615124     | BAO_0000219     |                |
|             9 |                 |              1 |                           | Homo sapiens      | 163.0          | 143B               |       80001 | N                   |                   1 | Intermediate    |                   | CHEMBL615125     | BAO_0000219     |                |
|            10 |                 |              1 |                           | Homo sapiens      | 163.0          | 143B               |       80001 | N                   |                   1 | Intermediate    |                   | CHEMBL615126     | BAO_0000219     |                |



source_headers: assay_id
variant_id
src_id
assay_subcellular_fraction
assay_organism
cell_id
target_headers: assays_ss_d
assays_vrnt_d
assays_src_d
assays_ss_sbclllr_frctn
assays_ss_rgnsm
assays_cll_d
column_mappings: assay_id
assays_ss_d
variant_id
assays_vrnt_d
src_id
assays_src_d
assay_subcellular_fraction
assays_ss_sbclllr_frctn
assay_organism
assays_ss_rgnsm
cell_id
assays_cll_d
output: {"column_mappings": [["assay_id", "assays_ss_d"], ["variant_id", "assays_vrnt_d"], ["src_id", "assays_src_d"], ["assay_subcellular_fraction", "assays_ss_sbclllr_frctn"], ["assay_organism", "assays_ss_rgnsm"], ["cell_id", "assays_cll_d"], ["doc_id", null], ["description", null], ["assay_type", null], ["assay_test_type", null], ["assay_category", null], ["assay_tax_id", null], ["assay_strain", null], ["assay_tissue", null]]}